2000 Ford Focus Just flush? Or flush and filter?

If you are going to flush the system it is best to change the filter at the same time. However with the amount of miles on your vehicle, and the fact that this may have never been done before, I would really suggest that you don't want to do this repair anyway. Typically when you have that many miles on a vehicle and you do a trans flush and fill for the first time it ends up causing more problems that it helps. This is mostly because after the fluid has been in there that long and for that many miles the transmission has begun to get "used" to it and when you flush it and remove the fluid and all of the other build up you usually end up running into more problems down the road. Good luck and I hope this helps.