By following this procedure you can install Vim on your phone and edit text files via telnet application on the phone.

First of all you need to have Telnet access. Then please download the utils and the vim archive itself above and read do the following steps:
1. First you have to download the "utils" archive. Connect your phone via Telnet
2. Copy lib and bin directories to /diska/ of the phone memory (you can copy the files on the memory card and then copy then via telnet)
3. Copy profile.txt to the /mmc/mmca1/ folder (that is your SD card)
4. Extract the vim_sd.tar.gz files (the usr folder will be in the root of your SD card
5. Via telnet execute the following command:
# ./mmc/mmca1/profile.txt
6. Start using Vim by "vim <filename>"

Download the utils HERE
Download the Vim package for SD card HERE