Hi and welcome to Beoworld ! 
The Beovox 2700 and 2702 grilles were originally glued on. No clips and any doublesided sticky stuff found here is not original.
When you are done servicing them, you can glue the grilles back on using small amounts of contact glue, I believe it's called Evostick in the UK. I normally place a drop in each corner and a few spots along the sides, top and bottom rather than one long run. It makes it much easier to get them off the next time.
Martin