Importing MIA presets?

for a specific reason, I have transferred computers on which I currently do any Maya work on, and in the process have managed to leave behind my MIA shader presets.

I have them on a hard drive, but do not know how to go about importing them back into Maya to become usable once again.

any advice would be greatly appreciated!

thanks guys :)

EDIT: I also just realised, all my previous basic maya shader presets (saved as MA. and MB. files) are also loose. which directory would I put them in, or could I just import these as and when I need them due to the file extension?