Thank you guys for replies. I didn't do anythink more whit this receiver, I'm just waiting for good solution.
I don't know how to buy stuff from Ebay... I don't have internet pay card I have only Visa card that can be used only in my country (Serbia) and, I need to be honest here, I'm stupid when it comes to banks and cards and credit and all that. I know how to pay in cash and how to get cash from ATMs but I don't know how to pay online. Even bigger problem is that just recently we are granted PayPall in Serbia and many of us didn't use it before and now we just don't know how it works
. And ebay didn't have option to ship stuff to Serbia, now I think that they do ship to world wide but I don't know how to pay
Now I feel embarrassed...
Well... I think that I know what I'm going to do next. Tomorow, when IT shops starts working again I will go and buy Logitech K270 Keyboard. It is not so expensive (~30€) but it is pretty good keyboard and it uses the same Unifying receiver then I can use it with mouse too.
But, it will be so cool if I could fix this one.
I will try to buy tomorow liquid flux and try to reflow this again. Should I buy soldering paste to? Or I don't need it...
Can I use this heat gun or not?