Replacement part: NTE527A or SK7333 (try www.mouser.com)
1) Cut the socket off and strip the wires
2) Solder the diode to the bare wires (little tricky - be careful here)
3) Coat the wires liberally with RTV silicone (available from an auto parts store) so there
are no bare spots that can arc.
4) Step away and power it up. Watch the HV arc like crazy. Power it off and go back to step
3 until the wire is sufficiently insulated so that it no longer arcs.
5) Done
These monitors are fairly simple to repair. I would start off by resoldering the header pins on the deflection board first thing, as they are typically the problem.