adding heated bed to my printer Monoprice Mini/Steadytech Mini

I have a Steadytech Mini printer but you may know it as Monoprice Mini but it's the same printer.
https://www.ebay.co.uk/itm/Steadytec...e/273944975924

So I'm thinking to upgrade my printer by adding a heating mat under the aluminium plate that I already got.
https://www.ebay.co.uk/itm/120x120mm...AAAOSws3lc-VRO

So after I stick the mat under the plate should I take of the original surface mat or just leave it?
I also noticed that under the plate the motors are mostly exposed so I'm hoping that some of the radiated heat don't damage the motor or belt.
For powering it up I will be using a external power supply.