Adding trim tilt to 70 hp evinrude

[dthomas1015]

I have a 1983 70 hp evinrude outboard. E70elcte

I found a trim tilt that looks like the bolt pattern fits
It is identical to the picture halfway down this post:

http://forums.iboats.com/johnson-evinrude-outboards/adding-power-tilt-78-70hp-johnson-458172.html

I've been looking online for a walkthrough for its installation and I can't find anything
Do I need to remove the motor from the transom to install the TNT?

Any helps would be great. Thanks