How to reduce the size of video to 700 mb
Ok one thing to note is the resolution of the video. Most 700mb torrents are not full HD. most are 720p or if they are 1080p they are in h.265

Assuming resolution is 1080p you can go from 2 gb to about 1gb without a huge drop in quality. The big issue becomes with the type of movie. Movies with a lower (smaller) color palette will degrade quicker because compression aims to make as many pixels nearby alike to lower the decoding time and storage space. It analyzes the video in varying block sizes and re-writes it. 

H265 was made to take 40% less space as h.264 while keeping the same visual quality. The issue with h265 is the processing power required to encode it. I have a server I use to encode mine and it still takes a long time. 

As for the way you would do it...

Use a video converter that allows you to control the bitrate. Adobe media encoder is a great option if you have it. For h264 you don't want to drop your bitrate below about 1-1.3gbps for the video. If you chose to go to h265 then you can drop the bitrate to about 600-700mbps and keep the same quality. all of this comes with trial and error.