Haha man after my own heart. You are doing about as many upgrades as I did. My Samsung laptop came as follows:
CPU: i5-3210M (Dual core, hyper threading 3.1Ghz max)
GPU: Nvidia Geforce GT 620M 1GB RAM (625Mhz Core, 900Mhz RAM)
RAM: 6GB
Battery 6-cell 48wh battery (4400mAH)
HDD: 1TB 8MB cache
Then I upgraded all of those parts and its at this now
CPU: Intel i7-3632QM (Quad-core Hyper Therading 3.1Ghz)
GPU: Nvidia GT 620M (865Mhz Core/ 1080Mhz RAM)
RAM: 8GB (Faster RAM too)
Battery: 9 Cell 78Wh
HDD: 1TB with 8GB SSD, 64MB cache. SSHD
All that gave me quite a bit of improvement.
Anyways yes your CPU is in a socket you can remove it easily. On the left of the CPU there is a sort of flat-head screw driver looking bit in the middle. All you have to do is turn it with a screw driver, it turns easy if its hard you are going the wrong way, and the CPU will then lift right up. Put in the other CPU, twist it the other way, and you are done.
The 3610QM is still the best choice, just to reinforce it. There are several things that go into this. The motherboard can only give the CPU so much power, and the laptop can only handle so much heat. Thanks to the 3610QM being a low power low heat version, it make the chances it will work higher, because it won't produce more heat than your current CPU while the others you listed would. It likely won't consume more power either despite having twice the amount of CPU cores thanks to it being a low power model.
In my system, I had to deactivate the turbo speeds on the laptop to get it to work stable and you might have to also. To explain what that is, you know how it says on the webpage on Ebay it runs at 2.3Ghz? That is considered its full speed, but it will push the speed up as high as 3.1Ghz whenever it is running cool enough so that it boosts performance. This consumes more power, and my laptop couldn't handle that so it would occasionally crash, but I deactivated it and it is still a lot faster than it used to be thanks to having twice the number of CPU cores.
Remember though, you have no way of knowing if it will work till you try. I think it probably will, but its impossible to know for sure.
For RAM yes 2x4GB is ideal. Preferably at fast speeds or low power or both. This is based on a number of things but its a lot to go through.
http
/www.newegg.com/Product/Product.aspx?Item=N82E16820231703
These are what I have and have pretty much the best specs in terms of how fast they work and how much power they use. Some others are a bit cheaper, but they get a little bit slower performance or a little bit higher power consumption.