They aren't really tabs, they are large pieces of aluminium, size of a pocket diary, with a kink in them. These slide up behind the upper section of the seat. Hope tis makes sense
Thanks seat backs removed can now seal all the gaps. Some slightly more detailed instruction which may help others.
1) Remove both seat squabs by lifting front edge and pull forwards to release from under lower edge of lower back rest.
2) Remove plastic boot liner, 8 socket head button screws.
3) Remove 4 M6 hexagon head screws through rear bulkhead holding upper back rest in place.
4) Push seat belt receptors down out of the way.
5) Pull lower edge of lower backrest forwards over seat belt receptors, continue pulling forwards and push down on upper edge of lower back rest. This releases two aluminium tabs which slide down from behind the upper backrest as the lower backrest is pulled out.
6) Push upper backrest down to clear bodywork and remove.
It took me about 10 minutes to do this the first time.
