My button was rusted to the handle so a few days of WD40 soaking got it loose only to find out the spring & washer inside was destroyed. I also was able to slightly tap the rubber handle to slide it off to reveal the mess. I taped the rusty button deep as I could so I could turn the bottom of the rod. Once the bottom of the rod is turned it can be taped farther back out to reveal the full length of the button so it can be removed. This button is threaded onto the rod so I had to heat it to get it off. This was critical not to twist the rod & break.
I started out with a 1/2" lag bolt & cut the threaded section off to get the shank I needed for the button.
I left the head on so I had something to hold on to while I drilled for the hole. I started out with a 1/8" hole & then followed with a #7 or 13/64ths" drill for the 1/4-20 tap.
I cut the head off of a 1/4-20 bolt 7 threaded the new button on to chuck it in my drill press for sanding with emery cloth.
I used a thick 1/4" washer not the cheap thin ones & ground off the perimeter until it fit inside the handle. This will slid onto the rod then the spring, & then the button. The spring I used was from a multi pack at HD . I used the 13/32 x 2 3/4 & cut it to a length of 1 5/8ths". Once I paint all my parts I will follow up up with the assembly. Thanks for viewing!