Yes it can. 
You will need to remove the rear engine carrier and the mounting bracket, the water pump crossover pipe and the crankshaft pulley. To get the pump out get one of those oil pump pullers like they sell for the old beetle engines. In fact it is the same pump as used on the 71 and later beetle engines. 

Why do you want to replace it? May be only a temporary fix. The pumps really don’t wear out although I have seen them installed with the wrong cover gasket and I have seen them get damaged from debris in the engine. 

Dennis

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of Tyler Hardison
Sent: Thursday, November 5, 2015 7:46 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Oil Pump Replacement.

Can the oil pump be replaced with the engine in place?

--t