Retro fitting remote central locking to octavia I

[octavia99]

I've just got a 99 Octavia I but it doesnt have remote central locking, is it possible to retro fit it, and if so what parts are needed and how hard would it be to do?

[Crasher]

There is a kit from In-Pro that gives you remote locking but it isn't like the original key system which is serious work to install.