How to update user programatically in jira plugin

[driver]

Hi,
you need to use UserService:

UserService userService = ComponentAccessor.getComponent(UserService.class);
ApplicationUser updateUser = userService.newUserBuilder(applicationUser).emailAddress("newEmail").name("newName").build();
UserService.UpdateUserValidationResult validationResult = userService.validateUpdateUser(updateUser);
if (validationResult.isValid()) {
    userService.updateUser(validationResult);
}