metal roofs are easier to install than you think. measure your roof get the metal and this will help
tools I used
tinsnips left and right
Step 1: Add Strips to the Roof
add strips to the roof I used 1x3 furing strips. This levels the roof and provides an air gap between the roof and the metal. mine are set on 24 inch centers. Use outdoor screws long enough to go through the strip,old roof and into the joist of the roof. continue this all the way across. I recommend using a string line to keep them straight.
Step 2: Repair Any Bad Spots
when you are adding the strips if you find any bad spots now is the time to repair them. remove any bad wood and replace. I had a few bad spots so I pulled the shingles off till I hit good wood. now replace the wood you removed. you can use plywood, or strips of wood. it doesn't have to be pretty. I had to replace about 12 inches of wood so I used a 1x12 to fill in the hole.
Step 3: Laying the New Panels
start at the edge of the roof making sure you are straight and square. I used 14 ' panels but you can use 2 panels to make it easier. if you use 2 panels start at the bottom and work up. the over hang at the bottom needs to be a min.of 1 inch. the top will be covered so you have some room to play with I suggest putting one screw on the panel till you have a few panels in to make sure you are good on the bottom gap. the panels have a ridge on them the second panel goes over the first. continue to put the panels in till you get to the end of the roof. if there is vents in the roof cut a hole for the vent. later there will be flashing to seal it. the last step is to install the ridge cap. this is simple place the ridge cap over the top of the panel covering the gap place the foam water strips. and screw the cap down hope this helps more to come on doing valleys and end caps