When trying to remove the spark plugs on my '11 c70 t5, the first one I tried, was really hard to remove(didn't force it), so didn't push my luck and reassembled.. Question is,,,can I spray some "buster" on the plugs and then take them out? I bought it 2yrs ago, so don't know when the plugs were changed. Its running good,,,just thought it might be good to change them. Have 86k on the car. Thanks for the input,,,Bill