how to remove a geberit impuls dual flush unit from cistern?

[minco]

this images says it all:

I have to remove a geberit impuls dual flush unit, as it has a leak, which causes the inlet valve to run all the time.

The problem is, the cistern is too narrow to unscrew the base. Is there a way to remove the J-shaped pipe?

 

[tomy]

Take the cistern off from the pan then unscrew the big nut on the underneath that you cant see at the moment .

 

[minco]

Take the cistern off from the pan then unscrew the big nut on the underneath that you cant see at the moment .

Thanks, but the screws for cistern are not really accessible from the bottom (a magnificently crappy job was done, whoever did it).

All I want to do is to avoid the leak, is there an easier way of doing this?

 

[minco]

tuned out to be this 'bubble' problem from the outlet seal:

//www.diynot.com/forums/viewtopic.php?t=166017

so I don't have to remove the base.

if you find this by google, do not buy geberit dual flush. it is a magnificent failure.