This video explains how to replace the guts inside of a toilet that is continuously running. I will replace the fill valve and the overflow tube. I use a suction gun in the video to suck out the water. Here is a link if anyone wants one.
https://www.tools4flooring.com/gundlach-853-the-last-drop-suction-gun-p-896.html?msclkid=11bc98dd5faf1d97b7bdfa15c6be141f&utm_source=bing&utm_medium=cpc&utm_campaign=**LP%20-%20Shop%20-%20Ceramic%20%26%20Stone%20Tools%20-%20Misc.&utm_term=4577541786571832&utm_content=662%20%7C%20Gundlach%20No.%20853%20The%20Last%20Drop%20Suction%20Gun%20%7C%20%2428.25