Help! FL2 guide pin boot won’t fit

Hi all
I’ve just changed pads all round including guides pins etc on my FL2. Rear is all done but I seem to have either created a rather annoying problem on the front caliper . I took both guide pins out on osf the bottom rubber boot came out quite easily but the top wasn’t having any of it.
I put this down to age etc so after prizing it out in 2 pieces I found it was attached to a piece of plastic which remains in the caliper presumably to help support the weight of the calliper itself. However there is no way I can see the rubber boot going in without a miracle. And I’ve tried!
I take it I’ve done something wrong here. I’ve double checked and Ive got the right kit.
Any help and advice greatly appreciated.
Cheers

Can you post a picture of the issue. I can't visualise the issue for myself.
The guide pins are normally a firm sliding fit in the caliper, but a dab of plumber's silicone grease helps keep the sliding freely.