How can I change the cursor from the one that replaces the characters in the line, the thick black box, to the regular cursor, the skinny line?
When you have the black box cursor on the eclipse you might be in overwrite mode just hit the insert key and you should be back to normal. Here is the link https://stackoverflow.com/questions/11237884/bold-black-cursor-in-eclipse-deletes-code-and-i-dont-know-how-to-get-rid-of-it Hope it Helps
Have you tried pressing on the INS button?