Its a complicated model and you aren't being specific. This is probably the most difficult model to print and fit up I've ever done and to add to your troubles if your printing in PLA you will get bending because the parts are so long and thin. I just checked my one from storage and its bent like a banana. This needs doing in ABS or PETG or something more stable.
I'm not sure if your problem is parts not fitting or you don't know how the parts fit or your having trouble printing the parts?