new plug wires won't snap on....and resistor question

[ht325i]

Hey guys, I just bought a new set of ignition wires from here and they won't snap on to the the spark plugs also from Pelican. It feels as if the cap on the spark plugs are too big....was I suppose to remove the caps before installation?? That might sound like a stupid question but I'v never had to do this with my other cars. This is for a 1990 325i. Spark plug#:12-12-9-061-869-M14 and Plug Wire#:12-12-1-720-529-M106. Also another question, when I looked up the blower motor resistor on the realoem site, it gave me two different resistors. I cross-referenced them to Pelican's parts: 64-11-6-912-633-M6 and 64-11-1-375-754-BOE. What's the difference between them and where can I find the second resistor so I can identify if it is also bad? I was able to locate the first resistor and it was definitely bad. Thanks, you guys always seem to have the right answers.