driven

I could definitely use some help re: reassembly. Mating those lower projections on the slide and the bolt carrier to the lower receiver are kind of difficult for me?

Any ideas as to how to re-assemble and mate the upper receiver to the lower one? I'm having particular difficulties fitting those two projections (on the bottom of the bolt carrier) into the lower receiver. Thanks in advance! P.S. Any links to an online manual for the MR-1?