Related keyword search:
" Blogger remove widget problem"
" No remove button on blogger widget"
" How to force remove blogger widget"
" Cannot remove blogger widget"
This is quite simple. The cause of "remove" button is disappear is because the "locked" function is true. So, to turn off lock/unlock this, just change the word "true" to word "false". I did this through editing blogger template/HTML.
Another way to solve this, please share. To continue with my method, you can watch the video i made to solve this problem.