Hi Mark,I didn't realise you'd actually GOT the truck....
It's very easy to get overwhelmed by the scale of things,like the others have mentioned write a list and check off each one as you go.
Many of us are, and have been where you are right now.
Make a plan and do your damdest to stick to it,try not to get sidetracked.
Top Tip.
If there's any small parts you remove for any length of time,apart from the larger obvious ones, "Bag and tag".
Get yourself some of those zip lock freezer bags and an
inky.
NOT for writing 'menchies' on bus shelters though

Write on the bag what it is.
Also invest in a set of clutch head screwdrivers (I think Trevor sells them or can get them at his place near Edinburgh).
They're not expensive and will save you a bunch of heartache....
I had a set I loaned to someone a while back,he obviously thought they looked far better in HIS tool box,I never got them back!
You could have had them....

If you can work out how to post pics,there's a guide in the left side bar,post them up and the "powers that be" will provide the help and advice you obviously crave right now.
Perhaps of an evening or weekend I could take a run over and see it in person,I don't claim to have the depth of knowledge most of the folks here have but I have been through the mill myself and if there's anything I can do (even offer a shoulder to cry on) just shoot me a message and we'll take it from there.
You're just up the road from me a wee bit after all...
First and foremost...don't panic!!
We'll get you there in the end.