Was wondering why this was in roofing but then noticed there is no mason's forum.
Some people can sit down, look at a project, figure it out and do an adequate job. Others couldn't tell you the business end of a hammer or screwdriver. Without knowing which category you fall under no one here can tell you "yeah, go for it".
The two things you should keep in mind are that it entails more than just slapping some bricks into some mud and, more importantly, there are serious safety consequences to consider if it is done wrong. Both during the project and with the completed project.
Since it's a cape cod, it is steep and going to require adequate staging, both up to the roof and on it. You also want to provide adequate protection for the roofing or you'll end up coming back here and asking us how to repair your damaged roof.
It's quite a task you are looking to tackle there. If you decide to do it, let us know how it turns out. We always get everyone asking questions and never returning to fill us in on the outcome. Makes us sad