You cannot from within the machine.
The only way is to transfer/re-record the tracks to an external destination and then back again.
The main difference that I am aware of is that MT2 is 16 bit and MTP is 24 bit.
The sample rate is also extremely important to consider, when deciding how to do the transfer.
If you want to combine tracks from different SONGS that were recorded with different modes - one MT2 and another at MTP - and also different sample rates - 44.1k & 48k, for example - then one re-record pass must be done through the analog path. The other pass can potentially be done through the digital path, potentially preventing further degradation of the tracks.
Depending on how many tracks you need to convert, this could be a relatively simple process that wouldn't take much longer to do than the time it takes to set up your machines and run the audio twice. It can get pretty complex, if you have many tracks and are limited as to what your other recorder will be - a computer with the right interface and software would make an excellent 2nd recorder for this purpose.
Hope this is helpful.