For installation purposes, you can check out the process of Chamberlain B970 available on YouTube. It can get you an idea of how it is hard or simple to install a garage door opener. In terms of time consumption, it almost takes your 6-7 hours to complete. The job may take longer, especially for the first time. It also depends upon the circumstances that whether you are replacing existing the old ones or installing a wholly new garage door opener. For instance, if you are doing the replacement, the time may cut down on some procedures. In this case, you will be using the old supports but not the electrical devices at all. It is recommended to use new electrical devices as they are comparatively more efficient than the older ones.