I fixed my kenmore washer myself and it works fine but am having trouble putting the cabinet back on it, does it slide on top of the metal frame (along the side on the bottom) or under it?

Both, the sides go on top of the rails and the front flange goes under the front rail.
1- Tip the cabinet toward you and put the front flange under the front rail.
2 - Tilt the cabinet away from you and the side flanges will sit on top of the side rails.
3 - Ensure the back end of the sides of the cabinet are down and flat on the rails.
4 - Fold the console down and engage all four fingers.
5 - Replace two console screws.
6 - Pat yourself on the back!