Best way to have a 0 seeder torrent to be active again?

Yeah man. Wait it out. I've got loads of torrents that I had to wait for weeks before someone finally came online with the torrent and I could get it.

Remember to reseed difficult torrents

Often times it is indeed possible to wait it out, but without knowing anyone that has the content waiting is all you can do.

You might want to start scouring for DDLs and start seeding it yourself though you could also just wait. I've had torrents sit on 0 seeders for months before someone started seeding again.

try to find copies of it using dht crawlers

Find it elsewhere then resurrect the torrent. Private trackers have requesting, may be useful

Maybe you find what you are looking for on other p2p networks like ed2k/kad or dc++. For old content are usually better than public trackers.

You can try using a debrid service like real-debrid.com. They cache torrents so people can download them at full speed. You can for example paste in a magnet link and if someone has already downloaded it, it'll most likely be in their cache and you can download it full speed. If not, it downloads the torrent from the existing seeders/leechers like a normal client

Adding more trackers?