Reducing the size of a very large .mkv

[ChienBleu]

I have a video in .mkv container (9150kbps, AVC, 1280x720, 24fps, 3h8min) which is huge even for its runtime (12,0Gb without audio). What I'd like to do is reduce its size while it still remains of decent quality. The problem is I'm a noob here. But I don't mind learning a thing or two. Anyway, I tried messing around with a few programs and tutorials. I demuxed it (or at least I think I did) using AviMuxGUI. Then I tried converting a short sample of video with Any Video Converter and with Avidemux, selecting different settings, but it either lead to bad quality ('squares' when playing video) either the resulting video was 'stopping'/'stuttering'/whatever is the english word for that. Since I don't really know what I'm doing, could anyone please tell me what container (mkv or avi), which codec, what target resolution and bitrate should I try to achieve a decent (BRRip) quality video of 4.4 GB or below? Thank you a lot.

[Baldrick]

uncropmkv, open mkv, change the bitrate(calculate with a bitrate calculator like VideoCalc ), convert.

[dylz]

Just open the video in avidemux choose avc or whatever codec and mkv container, select configure and two pass target filesize then enter what size to output the file like 4.4gb for example.