Avrdude Verify errors with 18k sketch

You should be able to do it inside the IDE. Locate your preferences.txt file (see the Preferences menu item to locate it).

Close the IDE.

Edit the preferences.txt file and look for the line:

upload.using=bootloader

Change that as appropriate. Not sure about your ISP, but something like:

upload.using=avrispmkii

(or similar) should do it. Save your changes and re-open the Arduino IDE.