So, you purchased the high mileage kit with all the extra goodies and you don't plan to install all of them.
Now, is the time to do it. The Crankshaft Seal replacement will be the hardest part of the job. Without the proper tools and holding devices, it will be quite difficult to break the center bolt loose and to torque the new one. Advice is to not use an Impact Air Gun on that center bolt, loosening or tightening!
Below, is a series of pics changing the front crankshaft seal on a 1999 NB ALH engine..
Below, crankshaft center bolt with "homemade" holding bar..
Below, crankshaft center bolt with holding bar and breaker bar with cheater bar
Below, view of cheater bar from above
Below, view of old OE seal leaking (about 200k miles on it)..
Below, old seal is out (used to self-taping screws to pull the seal)
Below, new seal installed..
Hope this helps and encouraging....