i took off the belt from my Simpson Minimax, but can,t put it back?

hi, i got a simpson minimax Dryer, and wasn't working,,, so i took off the Belt, took the Bowl thing out just to find it was the switch Operated by the Door... So i put it all Back together , but as I go to put the Belt on, there is now Slack in It, and as im as Mechaniclly minded as a Shoe,, i just need to know Excatly how,, i think it has a Twist in it, but not sure,,
Thankss,