Wow this thread is full of fail. I mean really... it is.
There should be no need to rock the engine forward to replace the 02 sensor. Buy the proper tools and get after it the right way, this is leading you straight toward something else breaking or a hospital trip, in a different car, because you broke yourself while fixing your broken car.
Go to your local Auto Parts store, buy ^^^ $10-15 and it's a life saver. Last thing you want is to strip out the stuck sensor and have a mechanic get involved.
After that a simple ratchet with a long extension, I think I used a 6" and a 3" last time I did it before I installed headers.
Use these 3-4 items and its easy peasy, if you have a angle joint that may make it a wee-bit easier but not needed.
Just unhook the plug for the sensor first, the slot in the socket is for the connector to stick out of and it will just slide down and unbolt. Put new on in with anti-sieze and reconnect and done.