I have a 99 f-150 with the 4.6, trying to change the #7 plug i believe on the driver side, can't seem to get on the socket on the plug, any idea ?

 

i usually use a swivel for that plug. you can pull the fuel rail up and have enough room to get to it

 

Like Matt suggested a swivel and if you're using a plug socket with a rubber keeper inside remove the keeper and use a magnet to pull the plug out once you get it loose. Sometimes with the keeper removed you can get the little extra angle with the socket so it will drop down over the plug.

 

Check the plug wire you pulled off and make sure the end of the boot didn't seperate and stay on the spark plug. Sounds obvious, but it's hard to tell unless you're actually looking for this problem and it's impossible to get a socket on the plug when it happens. If you're just having problems getting the socket down to the plug, disregard.