Trunk is opening but not holding in the upright position

One or both of the hi pressure assist cylinders have failed. They are the two black bodied, silver shafted rams on each side of the vehicle going from the car body to the deck lid. they should be around 11 inches long in the extended position( trunk/deck lid open). You can buy replacements at just about any auto parts supplier. I've seen them at Autozone, Pepboys, and Murrays for sure just to name a few. There is a little clip on each end that you can pull back with a small screwdriver and then the socket of the cylinder will pop right off of the ball that they attach to and you can either take one in with you or write down the number to take in and/or there is also a guide to select your vehicle for the right ones hanging on the display where they sell them as well. Just remember! It's a 2 person job! The lid is heavy and as soon as you pop one or both of them off the full weight of it will want to bump your melon! SO HAVE SOMEONE HOLDING THE DECK LID(TRUNK) WHILE YOU POP THEM OFF!

Here's a diagram on what mark is talking about

here it is