If you have kids the maintenance bit can be done by agreement and you needn`t use the csa though I use their on line calculator to determine what I should pay.
Consent order not striclty needed but as said you leave yourself open should circumstances change in the future and she decides she wants more money.
The bit up to decree nisi is easy. You merely have to state that you both consent to getting divorced and you can cite 2 years separation as the reason.
This is where I am up to now, just waiting for the judge to declare Decree Nisi, which means in principle they accept yhat you can go ahead .
Then the next stage is to get Decree absolute where you have to make financial disclosure regarding your assets,how they were split and maintenance arragnements for the kids and spousal maintenance.(If any)
Presume that if you have been apart for more than 2 years you have a sort of unwritten agreement on this anyway? In which case you might want a solicitor to formalise it as a consent order. Once the judge is happy that your wife isnt going to be left destitute that
s it.
Lots of solicitors offer a free half hour,for a donation to a charity of their choice if you just want to get some guidelines,though as said before the wikivorce site is invaluable.