Switching from General student visa to tier 4 dependant

Hi,
Im on a general student visa category and my husband on tier 4 student visa following a degree course at a university.
1.Will I able to switch as a dependant of tier 4 inside the country or do i need to go back to my country to become a dependant of tier 4?
2. How much money do we need to show?
3.I've got money in my account and also my uncle can give me the sponsor letter for me, still my husband needs to show maintainace cost for me?
Please help me to find the proper way to apply for the dependant visa.
Thanks

Please someone reply to my question, im really confused

http://www.ukba.homeoffice.gov.uk/visas ... ts/family/#

Additionally, you have to apply outside the UK and you can't use Uncle's bank statements.