diff --git a/src/main/java/mops/gruppen2/domain/event/AddUserEvent.java b/src/main/java/mops/gruppen2/domain/event/AddUserEvent.java
index 47bad11..9d298ab 100644
--- a/src/main/java/mops/gruppen2/domain/event/AddUserEvent.java
+++ b/src/main/java/mops/gruppen2/domain/event/AddUserEvent.java
@@ -3,6 +3,7 @@ package mops.gruppen2.domain.event;
 import lombok.AllArgsConstructor;
 import lombok.Getter;
 import lombok.NoArgsConstructor;
+import mops.gruppen2.domain.Group;
 import mops.gruppen2.domain.User;
 
 /**
@@ -16,13 +17,6 @@ public class AddUserEvent extends Event {
     String familyname;
     String email;
 
-    public AddUserEvent(Long event_id, Long group_id, String user_id, String givenname, String familyname, String email) {
-        super(event_id, group_id, user_id);
-        this.givenname = givenname;
-        this.familyname = familyname;
-        this.email = email;
-    }
-
     public AddUserEvent(Long group_id, String user_id, String givenname, String familyname, String email) {
         super(group_id, user_id);
         this.givenname = givenname;
@@ -30,10 +24,7 @@ public class AddUserEvent extends Event {
         this.email = email;
     }
 
-    public AddUserEvent(Long event_id, Long group_id, User user) {
-        super(event_id, group_id, user.getUser_id());
-        this.givenname = user.getGivenname();
-        this.familyname = user.getFamilyname();
-        this.email = user.getEmail();
+    public void apply(Group group, User user) {
+        group.getMembers().add(user);
     }
 }
diff --git a/src/main/java/mops/gruppen2/domain/event/DeleteGroupEvent.java b/src/main/java/mops/gruppen2/domain/event/DeleteGroupEvent.java
index 618b8d2..93b4fce 100644
--- a/src/main/java/mops/gruppen2/domain/event/DeleteGroupEvent.java
+++ b/src/main/java/mops/gruppen2/domain/event/DeleteGroupEvent.java
@@ -7,8 +7,8 @@ import lombok.Value;
 @Value
 public class DeleteGroupEvent extends Event {
 
-    public DeleteGroupEvent(long event_id, long group_id, String user_id) {
-        super(event_id, group_id, user_id);
+    public DeleteGroupEvent(long group_id, String user_id) {
+        super(group_id, user_id);
     }
 
 }
diff --git a/src/main/java/mops/gruppen2/domain/event/DeleteUserEvent.java b/src/main/java/mops/gruppen2/domain/event/DeleteUserEvent.java
index 8b6452e..3200fd4 100644
--- a/src/main/java/mops/gruppen2/domain/event/DeleteUserEvent.java
+++ b/src/main/java/mops/gruppen2/domain/event/DeleteUserEvent.java
@@ -1,15 +1,21 @@
 package mops.gruppen2.domain.event;
 
 import lombok.*;
+import mops.gruppen2.domain.Group;
+import mops.gruppen2.domain.User;
 
 /**
  * Entfernt ein einzelnes Mitglied einer Gruppe.
  */
 @Getter
 public class DeleteUserEvent extends Event { 
-    public DeleteUserEvent(Long event_id, Long group_id, String user_id) {
-        super(event_id, group_id, user_id);
+    public DeleteUserEvent(Long group_id, String user_id) {
+        super(group_id, user_id);
     }
 
     public DeleteUserEvent() {}
+
+    public void apply(Group group, User user) {
+        group.getMembers().remove(user);
+    }
 }
diff --git a/src/main/java/mops/gruppen2/domain/event/Event.java b/src/main/java/mops/gruppen2/domain/event/Event.java
index b2fad43..d227190 100644
--- a/src/main/java/mops/gruppen2/domain/event/Event.java
+++ b/src/main/java/mops/gruppen2/domain/event/Event.java
@@ -26,7 +26,6 @@ import lombok.Setter;
 })
 @Setter
 public class Event {
-    Long event_id;
     Long group_id;
     String user_id;
 
diff --git a/src/test/java/mops/gruppen2/service/GroupServiceTest.java b/src/test/java/mops/gruppen2/service/GroupServiceTest.java
index 472c38a..03fd9a1 100644
--- a/src/test/java/mops/gruppen2/service/GroupServiceTest.java
+++ b/src/test/java/mops/gruppen2/service/GroupServiceTest.java
@@ -36,9 +36,9 @@ class GroupServiceTest {
 
         eventList.add(new CreateGroupEvent(1L,"Ulli", null, GroupType.LECTURE, Visibility.PRIVATE));
 
-        eventList.add(new DeleteGroupEvent(44, 10, "loescher78"));
+        eventList.add(new DeleteGroupEvent(10, "loescher78"));
 
-        eventList.add(new AddUserEvent(900L, 10L, "Ulli", "Ulli", "Honnis", "FC@B.de"));
+        eventList.add(new AddUserEvent(10L, "Ulli", "Ulli", "Honnis", "FC@B.de"));
 
 
         Assertions.assertThrows(GroupDoesNotExistException.class, () -> {
@@ -53,7 +53,7 @@ class GroupServiceTest {
 
         eventList.add(new CreateGroupEvent(1L, "Prof", null, GroupType.LECTURE, Visibility.PRIVATE));
 
-        eventList.add(new DeleteGroupEvent(44, 1L, "loescher78"));
+        eventList.add(new DeleteGroupEvent(1L, "loescher78"));
 
         List<Group> list = new ArrayList<>();
 
@@ -66,7 +66,7 @@ class GroupServiceTest {
 
         eventList.add(new CreateGroupEvent(1L, "Prof", null, GroupType.LECTURE, Visibility.PRIVATE));
 
-        eventList.add(new AddUserEvent(900L, 1L, "Ulli", "Ulli", "Honnis", "FC@B.de"));
+        eventList.add(new AddUserEvent(1L, "Ulli", "Ulli", "Honnis", "FC@B.de"));
 
         assertThat(groupService.projectEventList(eventList).get(0)).isInstanceOf(Group.class);
     }