Batboard

What do I need to change the RX freq and correct pl (if needed) for a min 2?

Thanks

You need to acquire and install the correct 1st LO crystal and acquire and install one or two tone active filters(reeds, in common parlance) into the correct sockets in the Min II. Then you need to have available the RF test equipment needed to realign the front end on the pager so that it receives well at the new frequency(meets specs for rx sensitivity).
If you don't know your way around on the RF board, you'd probably also find the service manual helpful.