If your engine is not off time, your don't need to use the crank locking pin, as long as you mindful not to turn the engine over.

Set the c-clamps to lock in the cam positions.
loosen the bolts on the lower crank pulley, and then begin removing the belt.
because the engine still has compression it keeps force on the crank.

I have done my TB too many times for so many various reasons and never used the Crank locking pin because its such a pita to get to. Its located behind the oil cooler on the block and if I remember right is an Allen plug that looks like its very happy where it is. Trying to get that think out and then back in is going to lengthen the time of the job by a few hours. Its not worth it.

Instead for your own peace of mind grab a coffee and run too the arts and craft store and grab a yellow shake up paint pen. Place marks on everything so you know they have not moved.

I never had an issue going about it without that pin in place.
The only time I did install it was when I pulled my heads to replace the Valve seals, that's a little different because everything is coming apart.