How do I put the case back together?

'88 KDX 200 ... I have the bottom end of the engine case apart. I am trying to put the two sides back together. How do I get the crank bearings into the case? Do I need a special tool? Do I install the bolts and draw it together squeezing the bearings into place? I saw a video online where the guy froze the bearings and heated the case with a torch to get the bearings to drop into place. The bearings are still on the crank shaft. Please help ... :bang:

Got it!!! I stuck the crank shaft (with the bearings in tact) in the freezer for a few hours, heated one side of the case in the oven for 20 minutes and it dropped right in place, no problem. Thanks for the help guys!!!

I did not replace the bearings because they were fine. Brought it to a mechanic because the gears were locked up. Turned out to be the rotor. The magnets had broken loose. I put them back on with JB weld and now I am reassembling the engine. It ran great until the rotor problem, but at the time I did not know it was the rotor (apparently the mechanic did not know either until he had already split the case. Wanted to charge me $2,200 to replace almost everything. I chose to take it home in pieces and try to fix it myself. I hope I can do it. So far I have only spent $3.50 on new JB Weld. Wish me luck!!!

Thanks Again!!!