The holes in the radio use "din tools" which you simultaneously put in each side, press to the outside, which unlocks the radio allowing it to slide out. I haven't tried it with very slim screwdrivers yet to see if it can be done without the special tools. Just Google "remove radio ranger", you'll find them.
with a crowbar
Go to : http://www.cthreepo.com/blog/2009/09/swapping-the-radio-in-a-ford-ranger.shtml
On a 99 ford Ranger it is located right next the radio on the drivers side behind the dash. Remove the radio and you will see in bolted on the left side of the radio hole.
you have to have fan clutch wrenches
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remove trim around radio, remove radio, remove the airvent extension, computer is mounted on the side of the instrument panel. 1 bolt, and 4 connectors
yes
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screws on the back side of the steering wheel
Replace the radio.