Yes that is it. To open it , first unclip all the pipes and wires from the top then use either a large wrench (or a hammer and screw driver) and unscrew the top (anticlockwise), it is very tight. Make sure you clean it properly before you reassemble it as the smallest piece of dirt in the seal will create a leak.
Same filter as on my Ulysse 2.2 jtd but I cant get advice on the Ulysse section of the forum in regard to the tightening of the collar. There are green min and max marks on the filter body. The information on manuals I have state that the mark on the collar should not pass the max mark on the body but I have no mark on my collar with which to align to the mark on the body. Should I just tighten it to hell or any other advice?
The guy in the parts dept. of my local Fiat dealer tried to sell me the complete unit (new body with filter included) as he said most people smash the collars trying to open them. 90 euro (about £80) for the complete unit. I think I will go for an OEM replacement filter and give it a go. The worst that can happen is that I will have to walk a mile to the Fiat guy to get a complete unit and bolt it on!
Thanks in anticipation as I have been putting off doing this job for weeks.