Just back your drag off so the reel turns easily. Then just pull the line off the reel steadily. It doesnt take too long, and just wrap the line around its self loosely so yo dont creaste a shitty mess.

Then with the new line, feed it down the rod runners and tie it onto your spool using a fishing knot (my prefered is the uni knot). Wind your drag up on the reel so reel spool dosent slip too easily.  Look on the internet to see how to spool the line onto the reel, its easy but you must keep a little bit of tension on the line while you wind. What type of reel you have will dictate the methord of placeing the bobbon of new line somewhere while you wind the new line onto the reel. Look it up because it matters, spinner is different to overhead and Alveys.

I tension the line with my non winding hand holding a wet rag.

I did notice you profile had no information, so perhaps you could fill that in a bit so our information could be more suited to your fishing styles and equipment.

Good luck. Post a pic of your newly filled reel to give some feed back.

 What is a suggestion of the type of mainline? What pound and what type of line like braid or mono

If your budget is like mine, tight, any of todays 6lb lines will be great for flatties. I wouldnt bother with a leader if you buy mono line, the flatties over here are not big enough. The bream will appreciate the lighter line too.

If you can afford braid then go braid. Remember your knots need to be a bit different (read a little tricker to tie) and our will need to ues a leader between the braid and lures.

Give the 6lb mono a go, its cheap easy to use and hard to get wrong.

I seem to remember you posted something about thinking your line is 15 to 20lb range at the moment. Just have a think about the size of your reel. Fishing for Bream and Flatties with lures really works best with smaller reels and rods.

What ever you decide just have a go. Its better to go fishing than worry too much. Once fishing you can reflect on the information supplied to you over these last few days.

Good luck and tight lines.

 Thanks for the advice. I do have a small rod and hope that the flatties and bream like it more. It will also increase my casting distance.

I am a learner to catching fish and my rods were all bought in the mid 80's to 2000. Nobody in my family has had any real fishing experience. I will definitely buy the 6lb mono.

I really appreciate the advice.

 6lb is awesome!