A basic step in the hood pad replacement process that seems to be missing: how to open the hood to a vertical position. There's also no easy search term on the forum that yields the results.

For a 123 car there are two tabs on the hood hinges.
Let the hood go up to its normal 45 degree position.
Slightly compress the hood and push down on the driver's side tab.
Then release the passenger side.
The hood can now extend to a near vertical position as shown in many pics on the hood pad thread.
The tabs will re-engage automatically when you close the hood.

Note: my '83 300CD did not open vertically, more like 70-80 ish degrees before all spring tension was relieved.

Sort of described here

http://www.peachparts.com/shopforum/showthread.php?t=243514&highlight=hood+vertical