In my experience which is somewhat limited to 3 or 4 cable installations, including my own It is easier than BT. The one I did last week I did in minutes. Sorry can't remember the make of the wireless router but it was a cheap new one bought on Ebay.
Step 1, install the router software on the PC and, using a cat5 cable connection, set the appropriate parameters in the router, SSID security requirements etc. Switch everything OFF, remove the Cat5 cable, connect modem to router and boot in sequence, 1st Cable Modem, once all lights are steady, boot router, wait 30 seconds and boot PC. Once PC up and running fire up the wireless connection and once SSID is found click connect, enter the key, if you have set one up and Robert is you mothers Brother. It really can be a simple as that. However it is not always the case.