Tier -2 Change in Employer with same CoS Code

[PatelS]

Hello Everyone,

I am on Tier 2 General Visa, Now I have got new job so want to change employer with same COS code (2421). I need your guidance on following points;
1) What is the procedures for changing employer?
2) My new employer is 'A rated' Do I need to show maintenance fund if yes than I have maintained in Saving Account it will be ok?
3) I got my current Tier 2 Visa last year, that time I have given English test for English Language. Do I need to give English test again? (As I have given BULATS English test which is not valid anymore for UK Visa purpose although I am Qualified ACCA plus have 3 years of experience from this Country).
4) How long it will take to complete all transfer procedures.

Thanks In Advance.