Change Currency And Price Order

I would like to change the currency show up after the prices, right it's €99.90 and I need to change to 99.90€ and also instead of a dot put a comma.
Anyone know which file to edit?

There are options for both these inside administrator —> currencies

As sioulisn correctly stated, you can manage the currency's properties at the Administration → Currencies page. All the requested settings are present in the settings of the currency.

Also please check the following article: