There have been quite a few people on this site & Advrider, who've replaced worn grips on their heated grips, including myself. Some have done it because the grips were worn & others because the element needed to be repaired. It is perfectly straightforward to use a sharp craft knife to carefully split the old grip along it's length & trim the glued bits at each end. You then use 2 right hand grips from BWM (any dealer will order/sell you 2 r/h grips) to replace the worn ones. Hairspray, squirted down the middle of the new ones helps them to slide on easily & helps bond them in place as it evaporates.
If you don't like the BWM black ones, you will need to buy two pairs of whatever alternatives take your fancy & just use the r/h ones...