To manually set an exit node in Tor, do the following:
- Locate a node on the map
- right-click no the node, select Copy->Fingerprint
- Go to Settings, Advanced
- Edit torrc
- Add the following lines:
ExitNodes servername1, servername2, ...
- Replace servername1, servername2 with the fingerprint(s) of the desired nodes.
- Apply selection only (for those two lines)