Do not do it unless its about 55 60 degrees or more outside, a heat gun , an extra hand for sure , two screw guns, screws 316 ss , small ladders 2, caulk gun ..
1- Buy rub rail that was on boat it makes for a quicker job.
2- Start by removing old rail .....DO NOT PULL HARD IF STUCK !!! use a blade and cut free!!! so as not to damage gel coat..(Do not remove old end caps on old open/notched transom boats)
3- Make sure u buy at least 10' or so per side of boat... longer than the boat, you will need the extra length as leverage to pull on with a helper
4- clean old area and fill in "ALL OLD holes with either epoxy or your choice of PERMANENT sealer.
4- Assuming u have left it out in warmth not direct sun just 60 or better find middle crimp w hands mark with a white grease marker.
5- Start at bow assuming you have the ability to see the old line of rail well proceed, if faint then mark with painters tape every 6"......
6- Appropriate 316 screws and matching drill bit, two cordless guns(goes much faster if one person drills just ahead of person fastening
6- Star fastening at bow at mid point mark with appropriate 316 grade stainless screws, i recommend using a dab of sealant on each screw.
Put two to three screws on each side of bow point about 3" apart(AFTER FIRST SCREW HAVE helper pull with all might towards stern)
BE sure to run a bead of clear adhesive behind entire length as you r installing !!!
7- VERY IMPORTANT STEP. Go to stern next step involves pulling and stretching with all your might and putting a screw or two to hold the stretch at rear corners of boat.
8- go back to bow and tape in place along both sides, then continue to repeat every 6" or less and drill and fasten on both sides
9- Pull hard again and come around stern(on solid transoms finish in mid stern pull tight and fasten one side complete. then pull and heat to finish the other end, but make sure u r stretching as you go so you make a nice tight seam)
On open transoms finish back into existing rub rail end caps(put heat on last foot or so stretch and add a bit of clear adhesive b4 putting in end cap and throw a small screw or two in each end cap
There are free videos on line at Jamestown Distributors and on the tv show SHIP SHAPE!!!!