Unmarried dependant (Tier4) switch to married

Hi all,

I'll be grateful if you could help with the following.

I have a PBS student Tier 4 visa in UK. My girlfriend (now wife) had an unmarried partner dependent visa.
In the mean time, we got married (outside UK) and now my wife wants to visit me in the UK.

Due to the marriage, my wife changed her surname and permanent address, and got a new passport.

My question is: is there a way to switch her unmarried partner visa to married partner visa? Do we need a switch at all?

I think this should be a very common situation (unmarried partners getting married) but still there is not enough precise information on gov.uk website. Another way would be to apply again from scratch but that will cost us another £300+.

Thanks in advance!