Welcome to the forum mate, can you take some pics of the frame and the bits you have so we can establish where the kit came from & how best to help you. If the frame is all there then your job should be quite a bit easier. The thicker metal parts on the frame (i.e. not the tubing) should all be laser cut and you should have loads of extra tubing, laser cut brackets, suspension arm replacements, hinges, attachments, mounting points, exhaust hangers, etc etc.
If you dont have all these, then the kit is likely to be a splashed copy & really sorry to say, but your job is going to be incredibly difficult & you are highly unlikely to get any help or parts to finish your car from extreme.
Hopefully it isnt, and if so, you are pretty much at the same point I am with mine. I am assuming the previous owner lost the dvd, so you need to contact extreme to get the details for the video.
I would say the first job is to remove all the body panels & check all the welding that has been done so far. Check the fixing points and measure side to side & compare to see if it has been put on square. Then start with the larger panels & remount, fixing with little self tapping screws or clamps just to get a feel of the fit of the panels & which need tweaking or amounts removing etc.
One thing to remember is DONT BOND ANYTHING. The bonding is one of the later jobs & you have to be totally happy with how everything fits together before bonding any panels at all.
Once you have the build DVD it will all become much clearer.
Make sure you take plenty of photos and once we have your status changed to 'Owner' you can get a build diary going.
Good luck!