iirc there is 4 bolts under the caps and 1 in the centre (from inside)

but....

the 90 spec spolier is bolted in different places so you will need to clean to boot off propperly (as there will be a thick black line where it sat) and then redrill to boot lid for the 90 spec to fit.

Last 1 I changed i just swapped the bootlds over complete was soooo much less hastle