ive bought new fishin line out of gone fisnin but how do u change it???????????

Simple

Step 1: Take of old Line

Step 2: Tie new line onto spool and wind around 10 or 15 times CLOCKWISE

Step 3: Have partner hold spool with pencil through spool

Step 4: Wind the line in ensuring it is done with a bit of tightness

And as Gordon Ramsey says - DONE

quite simple leave about a metre of your old line on the spool make a very strong knot between new line

and old line and reel as stated clockwise also hold the line tight near the reel this prevent the line going on loose or have someone hold the new line tight while you reel simple as that