Don't be sorry, ask all the question's you need, that's what this forum is all about. We are all here to help each other and to share info.
I guess it would depend on the bike frame you intend to use.
Mine, a D-back Della Cruz bolted right up. From box to running took less then two hour's.
Some frame's will take a little more mod work and of course will take longer and your mech. skill's will also determine how long it will take.
Here are some link's for you that may help you along, and again ask away!
Instruction Manual - Gas Powered Bicycle Engines, Motorized Fast Bicycles, Motor Gas Engine Bicycle, Bike Conversion Engine Kits, Motor Assisted Bike Engines 80cc and 49cc, Peddle Start Motorized Bicycle Engine and more!