im at -65, so basically im screwed even if i read the book. and no i dont have a blunt weapon army to get minimum 4 per sortie, nor can i afford it. so tedious.
You're not screwed at all.
1) Gain a place to store prisoners, any castle or city will do. A village or the newly added hideout cannot store prisoners unfortunately. If you swear vassalage to Sarleon, they control useful castles near the Noldor border like Talonshield. Trade for these if you already own a different castle. If you own a city, trade the city for Laria since it's closest to the Noldor.
2) Relentlessly hunt down Noldor and just auto-calc the battles. They have a double auto-calc advantage, so be prepared to take losses. If you join a ongoing battle, they don't have the auto-calc advantage, but you get a smaller share of prisoners. Also remember that if you are going to join an existing battle, don't wait. If there's a 500 strong Noldor army but only 10/500 are still fighting, you don't get prisoner loot for the 490 that were wounded before you decided to help out.
3) Don't release Noldor prisoners immediately, save them all in the garrison you own. When you have 61+ Noldor prisoners, click the button to mass release them all at once! You will drop to -39, since relations can't be worse than -100.
4) Other boosts: There are 3 Noldor relation boosting books, each a one time +10 relations. Only one book can be bought from booksellers, the other books come from ownership of Ethos and Laria I think. Laria for sure has one of these books.