Help getting MFC5840 CN scanner functional in Ubuntu 9.04 and or 9.10

I'm still trying to find help with getting my scanner to function under Ubuntu. It once was functioning in 9.04 but ceased about the time Xsane updated from 0.995 to 0.996. I have dementia and cannot stay focused long enough to solve the problem. In fact I'm not sure how I got scanner working in first place. I remember trying command line driver install and then synaptic install prob. several times each and one day it worked. I'm starting to fade in thinking power as I write this. One problem I'm having is understanding su and sudo. Most times when I use su and then type password it says password not valid. Some times sudo works and I get to run a command but it seems flaky letting me run commands all day long or stopping working altogether. This all is too much like an impossible jigsaw puzzle and I'm lost for words even explaining it other than I'd like to get my MFC components working in Ubuntu without first having a stroke from the mental stress of trying to figure out what to do.
I don't know what to look up to tell you what is installed already though arking a link that toldme how to do it. I'm so bad while I was on the page I forgot how to do a screen shot of it for posting with a note like this.
Well I'm all wore out just typing this... will return and try to explain more later... Thanx%:)SW

Take it one step at a time...

Look at "Brother Scanner Driver Installation in Ubuntu" -

("without first having a stroke" - I had a stroke on Sunday 12th March 2000)


Help getting MFC5840 CN scanner functional in Ubuntu 9.04 and or

Thanx Alan, Tho I've been trying to use Linux for 10 years. I have memory problems called dementia which most times hamper my ability to understand, learn, and do new things especially cryptic computer stuff like this. I cannot seem to establish a base line of learning with Linux.
It also seems impossible to stay focused long enough to complete the task. It's a combination of all the above and more I guess. Command line gives me fits unless it's a copy and paste type situation because of the amount of memory required to use it.
I've been at this for 30 minutes or so and already so confused I have to nap/break.
I had a question about how to edit that file but having hard time formulating.
How to open and edit I guess woulfd be the question.
"open /lib/udev/rules.d/40-libsane.rules file as root." See itz hard for me to remember what I'm doing if I have to hold new learned info in brain at same time. They sure ought to be able to make these installs a bit easier...Thanx %:)SW
This page isn't auto notifying abd I can't seem to find the switch to correct that.
If your stroke comment is real I can Identify. I lost the right side of my brain cortex to scar tissue in a car accident 1981 105mph sideways into parked car. Crushed right side of head. Lost right eye too.