To uninstall Excalibur, just throw the Excalibur folder in the trash. You should also remove the file Excalibur Preferences in the Preferences folder. There are no other files to remove.
.dmg/Shareware World/Utilities/Text Processing/Excalibur 2.5.1/Excalibur-manual-html/Excalibur-manual/next_motif.gif){kind=small}
.dmg/Shareware World/Utilities/Text Processing/Excalibur 2.5.1/Excalibur-manual-html/Excalibur-manual/up_motif.gif){kind=small}
.dmg/Shareware World/Utilities/Text Processing/Excalibur 2.5.1/Excalibur-manual-html/Excalibur-manual/previous_motif.gif){kind=small}
.dmg/Shareware World/Utilities/Text Processing/Excalibur 2.5.1/Excalibur-manual-html/Excalibur-manual/contents_motif.gif){kind=small}