[V8] Heater Box hose leak

[Mark Kalbskopf]

I'm having a bad coolant leak which seems to be coming from the rear  
of the engine.
Everything looks dry back there, so I looked up by the heater core  
and it's leaking around the valve and maybe from where the hoses  
connect. (it's hard to see with all the leaves and junk up there!!)
Anyway, I'm gonna replace the valve and hoses from the engine to the  
core, but before I did, does anyone have some BTDT wisdom on the  
replacement?
Should I take the core out or not?
Is there anything else I should look at while I have everything  
dismantled?

Mark

90 V8 195,000 miles.