Default cwm for duos 2 gt-s7582

Hello everyone,

I rooted my galaxy s duos 2 gt-s7582 with vroot and now i want to flash it with custom roms so i downloaded rom manager but it says first set up cwm recovery or the another one there is i dont know its name...... when try io set up cwm recovery from rom.manager it says your device is not listed you have to do it manually.
Please help me how to do it on my duos 2 gt-s7582.