I have, on occasion, had to raise the mast myself on an N20. Being about 80 kgs myself, I seek all the assistance I can. In these situations I have found it helpful to use the spin halyard, and raise the mast while it is still on the trailer

My trailer has the bonus of having a mast cradle on the rear that holds the mast above the rear beam when trailering. I use this as a cradle while I am setting up.

I slack the shrouds to the top hole on their adjustment, allowing the mast to lean slightly forward of vertical once the mast is raised. Don't forget the pin in the mast base!

Next, I run the spin halyard as normal, and attach one end to the roof rack of my vehicle (pulling the trailer), or the brush bars on the front (if it's a truck). The other end goes through the spin halyard block as normal.

To raise the mast, I merely stand on the rear beam and bring the mast out of the cradle to my shoulder. Once I walk it up the tramp to vertical, I tighten the spin halyard and cleat it. This acts as a "temporary" forestay until I can put the forestay pin in the bridle. There isn't too much tension on the spin halyard because the shrouds are loose enough to let the mast lean forward of vertical.

Once the forestay is attached, I ease the spin halyard and untie it from the vehicle.