step by step below:
step 1. Download and install
Video converter for MacClick here to download it, After the download is finsihed, run the Video converter for Mac.exe file

Step 2. Run
Video converter for Mac and select your input video file
First you need to choose which video format you would like to convert.
To do that click the Add Files... button to select your desired format that need to be converted from the "file type" list in the pop-up window.

after loading the file you want to convert, click Effect...to define the rendered output effect

to crop out the uncessary part in the frame, click crop...to remove black sides, subtitles. if you just want to convert part of the video, then use Trim...to decide the output video length

Step 3. Select the portable device and output file format
select an output file format form the Profile... pull-down list.
You can easy tell what formats would a device supports.
Step 4. Convert video
During the next step you can specify the path for the the output file and its name.after all the settings work is done, you are ready to convert the video now. the conversion time depends on the paramerters you set and the file size itself.

you will see overall progress in percentage and on the progress
you can press cancel button to cancel the action
Step 5. Upload video to your portable
you need a cable to connect your portable device to your computer.