Any competent mechanic can change the booster, you need to build a relationship with the local Toyota guy as you won't want to drag the car a hour away every time something breaks. Remember, while some things require MB specific knowledge, these cars are pretty simple.

Brake bleeding isn't needed when changing the booster if you are not changing the master cylinder. However, if there is any fluid in the booster , leaking from the back of the master cylinder, you will need to change the master cyl.

Unbolt the master cyl, leave the lines attached, and move it aside. Remove the vacuum line.

From under the dash, unclip the booster push rod from the peddle then remove 2 to 4 nuts that hold the booster. Remove the booster from under the hood of the car. Install is reverse with a check of stop light switch adjustment when you are finished.