A Dummy's Guide to Replacing an In-Tank Fuel Pump

I've posted a few threads recently, trying to pin down what's wrong with my 940 wagon - threatening to stall on a regular basis. Various suggestions about AMM, fuel pump relay, etc. However, I failed to mention one aspect of the initial flare up of this fault (duh!):

The afternoon that this problem first arose, the fuel gauge had just given up. I'd thought this was just a dashboard fault and ignored it, thinking we'd carry on driving watching the mileage and guessing the fuel level. It was that afternoon that the car started to threaten to stall.

Reading another thread to day, the lights have come on!

?q=940+in-tank+fuel+pump&rnum=7#9ff022eee148ec37 There has been a whine from under the bonnet for a long time, but I've never really investigated it as there's not seemed to be a problem. Now, reading the thread I've referenced above, I discover that the whine could well point to a faulty in-tank fuel pump. If that pump has now completely failed, I guess that would explain why the car is threatening to stall all the time.

So, an in-tank fuel pump is just £36 from German&Swedish and, not being flush with cash, I'm hoping to fit it myself to save the labour charge. Am I being stupid, or is this job do-able?

If so, can someone please outline the basic pointers and give me something of a dummy's guide to replacing an in-tank fuel pump?

Thanks

Tim