You'll need to pull both valve covers, and all of the accessories from the front of the engine. Not an overly difficult operations to roll in a new chain and replace upper guides. The reason for pulling all the accessories (PS pump & bracket, alternator & bracket, cruise actuator [plus I pulled the distributor]) is to access the guide pins.
A chain guide is prefered for rolling in the new chain, as that keeps the chain from jumping a tooth on the cam, but with care and patience (plus a lot of zip ties) it can be done without one. There are three upper guides you want to replace, one in the right head and two in the left head. I found it easier to replace the guides before rolling in the new chain. Be sure to mark the cam sprocket and chain at the left head as you need to remove the sprocket to access the two guides.
Hope this helps.
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72
'02 CLK320 Cabriolet - wifey's mid-life crisis
2012 VW Jetta Sportwagon TDI...at least its a diesel
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