They're probably right about the instructions not working for you. The USA system is radio-based with rolling codes & some type of ID/serial# encoded into the remote fob. The car has to be programmed to 'know' which remotes belong to it.

The IR system that's used in UK is completely different & we have no way of knowing what is the procedure.

The procedure given on this site comes directly from the Helm repair manual, so a UK version of that book probably has your procedure. I think there's some scans of those books on-line somewhere, can't remember where, & probably not allowed to post it here anyway. Google might help you find it??