what to do with factory phone

[Joel 89 750il]

I recently purchased an 89 750il.
It has the factory installed phone/hands free kit.
As there are better hand held phones on the market, are there any suggestions for removal, replacement or adapting newer phones to that spot. I would like to continue using the built in microphone, etc.
Any suggestions or links to instructions are appreciated.
Thanks
Joel

[NeeDiT]

i question why should you leave the phone in there... i had a factory phone in my 325i but i removed it.... it's a PITA as it has all kinds of wiring going throgh so i did it ruff and just cut the damn thing out also cut the mic from the sunvisor too... removed the unit from my trunk. anyway from what i saw when i was taking it out you'll be better off to pay somebody who knows how to do it and get the new unit installled for you.

i think a cell phone is good enough these days

my .02 cents