Help!

[97chevy350]

My oil cooler line has been leaking for a while now and i really need to get it done. I have had the new line for a few months but havent gotten around to it. I started to do it once buy i decided i would wait till i changed oil. So not having time to do the line, i have put off changing oil im about 600 miles over and i have a really tight schedule, so im plannin on doing it in the morning. It doesnt look like a pleasant job. It is the one on top where it goes into the filter housing or whatever you would call it. Whats the best way to do the job and what about sealant/teflon tape on the fittings?