Should I use more thermal paste?

I received a new heat sink from Dell for my Studio XPS 9100 desktop (Intel i7 960 processor). The new heat sink came with a thin layer of fresh thermal paste completely covering the circular contact area. The new thermal paste was protected by a green plastic cap over the contact area. I had already purchased a tube of Arctic Silver 5. Should I:
1. Install the new heat sink without adding any Arctic Silver to the CPU since the contact area on the heat sink is covered? or,
2. Add a vertical line of Arctic Silver 5 to the CPU and then install? or,
3. Remove the factory thermal paste and apply Arctic Silver 5 to the heat sink and the CPU to avoid mixing two different kinds of paste?

I am leaning toward alternative #1 since I assume the manufacturer would know best what paste to apply and how to apply it. Any ideas?

I'd just #1, it's a stock grade heatsink anyway.

Thank-you, Beers.

#1. If it was an aftermarket cooler I'd look to replace it using method #3. Do not do #2 as that would be an excessive amount of thermal paste and it would make cooling performance worse and likely spill over onto the sides of the CPU.

I've been in the same position as you and went with #1. I also want to 100% agree with Geoff do not do that at all.

Lastly what have you decided to do and has it worked?