And, if the boat / sail has not been used for some time, you may well find that the bolt rope (the bit that slides up the track of the mast) has shrunk.
You can “unpick” the lower end of the bolt-rope (just near the cunningham eye / rope) and then re-adjust the length, and then sew it up with a couple of stitches. This may well help the sail to be raised the last few inches to the top of the mast.
But, as everyone else has said, the important things are:
– slide the sail onto the boom.
– Make sure the kicking strap is very loose.
– Attach the pin at the tack (forward, lower corner) and the “string” / outhaul at the clew (outer, lower corner).
– Pull the sail up the mast: the helm / stronger does the pulling on the halyard, while the crew does the feeding to ensure it goes up the track smoothly. (Someone will have put the boat head to wind before this point!)
– Make sure the kicking strap is very loose, otherwise you wont get the sail up far enough.
– Leave the boom swinging free. Pull the halyard up very tight: to get the sail as far up as possible, and to remove any stretch in the halyard.
– Fasten the halyard off. Then pull DOWN on the boom (sometimes this is a 1 person job, sometimes it takes 2) and put it onto the gooseneck (that sticking out bit of metal on the mast).
– Then attach the kicking strap. Or this might be already attached, and just needs tensioning a little.
– Do NOT tension the kicker too much – allowing the boom to raise when the wind blows helps to stop the boat rocking about too much before you are ready to sail.