Just in case somebody need this info, this is the answer of the manufacturing companie:

"PCCHIPS Support (USA) Posted : GMT 2008/05/20 22:14:14
You should have no issues removing part of this clip. It is NOT recommended that you [remove] the whole thing if possible, so it can stil be clipped in place."

Also a technician told me that he have to do that (remove part of the sideclip) all the time (sic).

Cheers

Gustavo