how to update the ‘Comment’ field description on RIKI page at page level

[Lakshman]

i want to remove inside Comment description text "write a commet.." i need to write some other commets text in that place

[Nic Brough -Adaptavist-]

You'll need to hack the core code to do this.  The message is built into a language file, so you should just change that.

Given the annoyance of having to unpack the files, find it, edit it, repack the files and redeploy on every migration and upgrade, I'd question if the effort is worth it.