Here is a nifty little trick for easily tying new line onto an empty spool using your baitcaster's wiffle spool. A "not so obvious" technique that will save you much frustration. Definitely worth taking a look at!
Let me give you a quick tip on how to tie fresh line onto an empty baitcaster spool. If you take a look here, we're going to take the line and thread it through the worm gear, or level wind. Now take a close look, because this is where most people have a lot of problems. They try to figure out how they can wrap the line around the spool. They'll try to thread it under and come back through to fish it through with their fingers.
All that stuff is unnecessary if you have a wiffle spool. Here's the tip. Take the fishing line and simply insert it into one of the holes in your wiffle spool. Spin the reel to get that line to come through to the other side, just like so. Grab the line and you're good to go. You are now ready to tie your double overhand knot. That's all that is needed. It is as simple as that.
Just put the line in the hole of the wiffle spool, give it one revolution and tie it off.