First of all, I don't really know what you mean by "digital filo", like a digital agenda or something like that? Either way, whatever you're going to do with it, choose what kind of applications you think you will need. If you will use it as a digital agenda you can rip the camera application, the browser, any music application, social media application(s) etc. This
post might be able to help you to determine which applications are safe to remove.
How you remove the applications can be done in different ways, you could use a file explorer with root, you could use ADB, you could modify a ROM (ie. delete the files you won't need) and then flash it. Either way I'd recommend you to make a either a full backup of your system (Nandroid) or backup the application itself before deleting it.
Note: when deleting an application, also write down the permissions the file had.
I hope I've helped you in some way!
"However, if you put any trust in Benchmark Scores you could use them
to prove that dancing naked for 5 minutes in your garden affects device performance" - Chainfire