Instructions for my TMP model, more information is in the slideshow.
Step 1: The Handle
Easiest step, just follow the photos.
The broken white rod isn't needed, just use a normal one.
Step 2: Front Body
The front handle / angled part is tricky to get in, everything will stay in place when it's finished.
Step 3: Back Part of the Body, and Finishing the Gun
Not that hard
Step 4: Red Dot Sight and 'magazine'
The red dot sight is optional, but it looks better with it, in my opinion