Hey bud,
I had similar probs with rear wiper on my BRAVO, it eventually stopped midsweep and died! I still had an intermittent live feed to the wiper which it should have as its an internmittent set up, but the motor was dead.
The wiper arm is held in place by a 10 or 13mm (cant remember) nut found under the lift up cover on the outside of the car, mine was a bit tight too, just spray the nut with wd40 and leave for 10 mins then just pull the wiper blade towards you when you are facing the rear of the car. I found that pushing down on the left side of the wiper blade with one hand and pulling at the nut end with the other hand the best way to get it off, you can pull on it as hard as you want as the wiper arm/blade is quite tough and it doesnt matter if you damage the motor is it will most likely be knackered anyway. I ended up getting the pliers on mine and it just popped off.Before trying to take the wiper arm off remove the interior boot trim panel so you can then see the motor, make sure the multiplug is in good condition and is firmly in place in the wiper motor, also check your fuses under the dash. If everything else is ok you need to then replace your knackered motor. With the boot trim panel off and the wiper arm removed, just undo the three allen key type nuts that hold the motor to the car, also remove the multiplug and pull out the rear screen washer hose. Thats it, now obtain your new wiper motor and refit.EASY.
I ended up getting a used wiper motor from an older BRAVA. The motors and the mountings for them are exactly the same, but the multplug which plugs into the wiper is slightly different. The both have 3 wires feeding the motor and they are the same colour so i just cut off the bravo multiplug and solder the brava one on. I then mounted the wiper and it works fine. I paid 17 quid for mine which was a good price, new from fiat are about 90 quid! But dont pay more than 25 quid for a second hand one, they come up on e-bay from time to time just keep your eye out for anyone breaking any age/model bravo/brava and make them an offer on their wiper!
Hope theis helps,
Tony.
P.S. Sorry for the essay am bored at work.