Shouldn't be too difficult. I've done it twice before and don't recall it being outrageously tight. How well does the 'bitch clip' (#3) fit into the sle.eve? I ask just to confirm whether you have the correct part. How does it compare with the old one?
Sorry I can't be more help. I'd just jam it in there and hope for the best. Worst case is you have to get a new one (from the dealer this time).
Dave