Bricks, Masonry, Asphalt and Concrete - cleaning out mortar joints and repointing brick

i am going to start a repointing project on my house and wanted to know the best way to cut out the old mortar. Is hammer and chisel the best way or are there other faster ways to do it?
also, my sprinklers have pounded the walls around my house and there is some algae or mold growing in my mortar joints.... should i attend to that first or just remove the old mortar and begin to repoint- my plan is to eventually complete the whole house - is there any thing else i should know before i begin?

( no bricks are loose BTW)

thank you
alex

A 4" angle grinder with a diamond blade is the fastest way (buy a tucking blade if possible, it is 1/4" thick) . Buy a portable fan to blow the dust away from you and wear a particle mask. You do not need to clean the mortar before you tuck it, but it would be best to solve the problem of the sprinklers, then clean the entire surface before you point.

If you have never done it before, I recommend using a hawk and caulking trowel for the horizontal joints and a grout bag for the vertical (head) joints. After you fill the joints, let the mortar take an inital set, then tool them. Work back and forth between filling and tooling. I can do an area about 25 square foot at a time on average. Don't get ahead of yourself on filling, because if it sets too much, you will have to take it out and start over.

If you are using premixed bagged mortar, buy a bag of Type S lime per 20 bags of mortar, and throw a big (consistant) handful of lime into each bag mixed.

can i not use a grout bag for all of it?

Sure you can, it is just hard work.