Where to start?

You would first need a Nokia handset that's capable to be flashed without special hardware (E52 AND e90 can do this with NSU).

But you would need a custom ROM image that fits onto the E52 or E90's internal ROM that contains a Maemo image.

That Maemo image would also have to be compiled to work with the CPUs on those Nokia handsets.

It would also have to be modified to include hardware drivers for all of the hardware on the handsets which is radically different then the hardware found on any maemo device (Bluetooth, GSM, UMTS radios/GPU/display device/keypad input devices/Sound chip/ etc...).

To top it all off, most of the drivers for the hardware found on Nokia handsets is closed source and incompatible with their open source counterparts.

So in short... No you can't.