take the foldy parts out of the headtube. then get these bolts:
1 x 3/8" by 2 & 1/2"
2 x 5/16" by 2 & 1/2"
get 2 washers & a nut for each bolt.
the 5/16" bolts go in the bottom & front holes on the headtube, the 3/8" bolt goes behind the headtube (through the rails.)