Well I did get the seal changed, I ended up pulling the gearbox off the car and using a pair of decent quality needlenose on the snapring. Which bent, but I was able to get the tip of a compound angled pick behind it, so I could get the hook pick through the hole, and with the help of a screwdriver I ripped it out.
40 minutes start to finish. If I only knew. Heck good thing I didn't, I'd've probably changed everything I touched including the gearbox!
But now, the timing chain on the '03. Here's my post:
The timing chain tensioner warning level has gone from 'slightly noisey' to 'dang I'd better get on that'.
For those who don't know, the tensioners on Panther 4.6s from 99-03 (and others?) have a known factory defect, the plastic coating on them wears through and eventually the metal too. When I bought my car at 54k? (darn memory) last year it did have a slight ticking noise at startup and now with around 65 it has gotten worse, and more worrisome it got worse suddenly. I suspect the plastic on a tensioner came completely off, or at least wore completely through. I'll know soon enough.
I was really, really apprehensive about a 2 cam timing chain change until I read Dereck's most excellent 'TIMING THE CAMSHAFTS ON A 4.6L TOWN CAR' article over at LincolnsOnLine. If Dereck says it's virtually foolproof then it's the job for me!
Already picked up the gasket set, Fel-Pro TCS4586, around $20, and shortly I'll pick up a Cloyes 9-0387SG Multi-Piece Timing Kit, around $225:
This is the front of a 4.6 with the timing cover off, showing the chains. The tensioners are the curved bits:
A little different than the 85 (not mine, pirated):
And much more expensive

The 85's cost about $40, and it was a HD model I'll never have to change again, while the chains for the 2003 are basically stock replacements.
There are upgraded timing kits out there for the 2003 but the price goes up FAST. I am open to suggestions.
I'm going to pull and reinstall the water pump, I already picked up the gasket. My neighbor has a power steering pulley puller and I'll borrow a harmonic balancer puller from the parts store.
A few questions if anyone has any idea:
Anything I should watch out for?
Anything else I should do while I'm in there?
Do I REALLY have to spend $20 on a crank bolt, and are there any other bolts I need to replace? These are some kind of bolt called 'torque to yield', use them once and throw them away.
I can understand the timing chain difference, as the 4.6 gets more stock HP and better gas mileage than the 5.0. But why the heck can't they use bolts that you take off and put back on??
Pete