converting visitor visa study permit

[a1186k]

hello, please share and help with the following!
what are the requirements for converting tourist visa to study permit from within Canada?
does the person applying need to leave Canada?
can someone convert their student visa to study permit to complete high school in Canada? (given he/she will pay the fee of course)
in such case where a minor is applying and his/her parents are not in Canada, would his/her older sister (23 yrs.) be considered a "custodian"/ "guardian"
in case as such, are approval rates low?

 

[a1186k]

http://www.cic.gc.ca/english/helpcentre/answer.asp?qnum=741&top=23

https://www.canada.ca/en/immigration-refugees-citizenship/services/study-canada/study-permit/eligibility.html

https://www.canada.ca/en/immigration-refugees-citizenship/services/study-canada/study-permit/apply.html#within_canada

Thank you for the input!

 

[a1186k]

I had a few more specific question, the answers to which I couldn’t find on the links mentioned above.
What after the minor goes to Canada and get a study permit, finishes her highschool and wants to go to college there (she won’t be a minor anymore). Can she still apply to renew/ extend her study permit
Also can she get a work permit with a study permit?
And let’s say she is able to convert her visitors visa to a study permit, however her visitor visa are about to expire. Does it matter as long as she has visas valid enough through processing time?