For a 1993 Mercedes-Benz 300E, there is a problem with step for reinstalling the cam sprocket

The actual step states for reinstalling (from Pelican Parts), "If you have not moved the cam or the crank you should be able to reinstall the cam sprocket and everything should line right up. If you have sent the head out for work, moved the cam or the crank while working on the engine things will not line up and your witness marks will be useless. You will need to set both the crank and cam at TDC for installation. If you did not move anything and everything lines up correctly, it is a good idea once the chain tensioner is re installed and everything is torqued to rotate the engine from the crank to Top Dead Center and check that everything lines up with the witness marks just to be safe."

The problem is, the crank and the cam cannot be adjusted to top dead center (TDC). The left guide rail (I believe that's the name of the part) keeps putting more tension on the timing chain as the crank and cam get closer to top dead center. This makes it impossible to put the cam sprocket back on. The left guide rail I am referring to in that picture is directly bellow the middle yellow arrow. Does anyone have any advice to align the crank and cam with top dead center?