Sometimes. It depends on if your particular address is eligible for a self install. Most are, but not all.
Make sure you make an appointment to get any equipment..
I agree with Paul. Most likely you can do it yourself, but not all addresses allow it. Also, be sure to ask Comcast about whether you'll need a splitter on the line to connect both WiFi box and a DVR.
There are modems available for rental at the store
Thanks! Your answer is awaiting moderation.