Hood strut replacement on a 944 is fairly straight forward. However, I've offered a few tips here which may save you some trouble during the installation. It's best if you have an assistant help you with the installation.
Needle nose pliers
Flat tip screwdriver
944 511 351 01
Raise and prop open the hood. An old broomstick cut to appropriate length works well.
Install one side at a time.
Using the needle nose pliers, remove the spring clips for the hood strut retaining pins. You may also need a flat tip screwdriver to disengage the clip from the pin.
While supporting the hood, remove the strut retaining pins and remove the old strut from the car.
Install the new strut and attach using the retaining pins. If the new strut comes compressed and held in place with a strap, do not cut the strap until you are ready to install the new strut. The new struts will be difficult to compress for installation. Installation of the new strut may require the hood to be raised slightly higher than it's normally raised position. DO NOT allow the back edges of the hood to press against the windshield as this may result in a cracked windshield. I've seen this happen many times.
Install the spring clips onto the strut retaining pins.