LOL that dose not look fun at all
In the S14 FSM there is a Digital wireing diagram, use it and follow what leads where
it should give you a road map to rewire this thing.
From what I remember there are a few wire that you don't need in the conversion so there will be some extras as well as a few that need to be spliced together.
S14 FSM (remember the s13 one only has the USDM a/c guide)
Manuals > JDM and European Cars > S14 Silvia - Zenki (SR20DET) - Nissan 240SX Performance Tuning
and another useful site:
Nissan 240sx Performance, Modification, Repair and DIY Articles - by NICOclub.com