parking specs

I need help. Recently I have donwnloaded AFCAD 2.0. Also in the past week I have download several commercial jets including meljets B747 pack and a AFCAD file for Charles DeGaule airprt (LFPG). Now here's my dilema. I would like to make this and other airports look denser in the sense of having more aircraft at gates and ramps. Not just the FS9 defualt but also other aircratfs I have dwnlded. I followed the instruction from the afcad PDF file but I am still foggy on how to put a particular aircraft, at a particular gate, at a particular. I am an intermediate user and maybe not aware of additional information.