It's pretty common for people to upgrade their desktop computers.  They are built to be opened up and have parts switched out.  But laptops are much scarier.  For one, they are, byte for byte and hertz for hertz, much more expensive.  Also, they are smaller, and you might feel that they are easy to take apart, but hard to put back together, sort of like refolding a map.  And, finally, the parts are usually not generic and interchangeable, as the parts of a desktop are.  A CPU fan for a particular Thinkpad T30 will certainly not work for any other laptop, often not even another Thinkpad T30!

But I have found that, when I bought the parts carefully on eBay and downloaded the appropriate documentation from IBM, I was able to do an upgrade far more easily than I thought possible.

I have an IBM (Lenovo, now) Thinkpad T30.  It had a Pentium M 1.6mhz processor.  The computer was working well, but in the last few months, it often wouldn't boot, giving me a "Fan Error".  I downloaded the IBM maintenance manual for this model, the 2366-M1U.  That number is crucial!  You'll find it on a label on the bottom of your laptop.  Thinkpads all have a four-digit series number, followed by a three-character model number.  So each IBM laptop is uniquely identified by these seven characters.  You can go to Lenovo.com and search under that number, and all documents related to it will come up.  If you find the Maintenance Manual, you will be well on your way.  These are very clearly written manuals, that take much of the mystery out of opening up your laptop and swapping out its guts. 

Before you do anything else, read that manual, or at least the parts relevant to your problem.  I discovered that, if I removed the fan, I would expose the CPU.  Also, I discovered that the CPU was a snap to take out and replace. 

The Maintenance manual will tell you the part number, or FRU (I don't know what that stands for; maybe Field Replacement Unit?), of each part.  You can then search eBay for that number.  I found several sellers whose business is to take dead laptops and "part them out", taking them apart and selling the good bits.  I bid on a refurbished replacement fan and a 2.4ghz CPU to replace my 1.6ghz model.  I then went to my local PC store and bought a small tube of thermal grease. 

Be sure to back up your hard drive!  You should do that regularly anyway, but CERTAINLY before doing any surgery on the laptop. 

The next part may be the hardest:  finding about an hour when you won't be interrupted.  Then make some clear space on a table, gather all the documentation, have a small screwdriver (for the Thinkpad, all I needed was a small Phillips head screwdriver), and get to work, following all instructions.

The only part that was a little tricky was applying the thermal grease to the CPU.  I downloaded the manufacturer's instructions and did it pretty easily.  You can't use too much, because it's basically made of silver, and you don't want to get any on the chip's leads.  And you can't use too little, because you don't want any hot spots. 

Ultimately, it will be a rewarding process.  You will save a lot of money over buying a new laptop, and you won't be intimidated by opening up your Thinkpad.