Click the Replace All button on the Search toolbar of the AceText Editor to search for and replace all search matches in the scope set in the search options. If you turned on the “all clips in all collections” option then the scope is all clips in all collections. If you turned on “all clips in this collection” then the scope is all clips in the active collection. If you didn’t turn on either option, the scope is just the current clip.
If you turned on the “prompt before replace all” search option then the Replace All command shows an “Are you sure?” dialog box before it does anything. This dialog box lets you see and toggle the “All Clips in This Collection” and “All Clips in All Collections” options. It also lets you turn off the prompt and choose which clip parts to make replacements in. If you toggle any options on the “Are you sure?” prompt then your new options will be used by all search commands until you change them again.
AceText does not have an option to prompt for each replacement to be made. If you would like to make replacements selectively, begin with the Find First command to select the first search match. If you want to replace the selected search match then click Replace Current and Find Next. If you do not want to replace the selected search match then click Find Next. Either way the next search match will be selected. Continue clicking Replace Current and Find Next and Find Next to replace or not replace each search match until no further matches are found.
The benefit of replacing matches this way is that you're not stuck in the loop of a Replace All command. You can make other edits between making replacements. To continue replacing matches simply place the cursor near the position where you left off and use Find Next or Find Previous to go back to the match that you skipped.