Is it ok to change the transmission oil from the dip stick chamber by removing it with a plastic syringe?

That is how a lot of the flush machines do it anyway. It will be just fine. Take out all you can, and then put back how much you took out. Run the car for 5 minutes, shifting through the gears with your foot on the brake. Then repeat. Don't force the tubing in too hard, you'll slide into the pan easily but you don't want to bounce it off the bottom of the pan and force it up into the gears. I personally would never bother with the filter on that car, they are usually just a screen on toyota cars.

Yes, but it's going to take you a long time if you think you're going to be doing it 50ml at a time.. You may have issues with holding enough vaccuum with the 50ml syringe to pull any amount of fluid up the tube. You may have issues with the tubing you have being too flexible to go down the tube or reacting with the fluid.

Also, chances are every time you remove the tube you're just going to spray/drip the 50ml you sucked up, all over the place so it'll be a big mess.

If you just get a fluid extractor it will use the same suction theory but do it much faster and efficiently (Mityvac)

Example:

http://www.amazon.com/Mityvac-7201-Fluid-Evacuator...

On my car, I use the extractor and it removes 1.8quarts (out of the 10total), which is the same volume as a drain/fill. This is also on toyota.

For those saying you should drop the pan to replace the filter-it really depends on your car.

If your car is so old school that the transmission is literally wearing itself and creating metal and particles under normal usage, then I suppose you need those extra measures;

If it's a modern transmission, where the factory specification is like 60k-100k services for just a FLUID change, then this transmission has been designed where it isn't shedding anything into the fluid to begin. It is a sealed system so shouldn't be contaminated. So I don't think you need to change the filter or drop the pan or anything like that with a modern transmission, (unless mentioned in the manual).

I don't believe your Toyota needs the pan drop or a filter change (it's just a screen as other person said). That being said, as a 07 corolla, i believe your transmission fluid doesn't even need changing after 3years anyway.

Do what you feel best for your car. Ok now on to some other stuff. My toyota has a metal screen tranny filter and does not need to be changed as often as the fiber mesh filters it does not catch as much particles but it does the job just the same. I try to change my tranny fluid at least once a year due to a high milage older car. my 1990 toyota still is rockn n rolling at 247,000 miles. currently on jacks for cv axle change. I warn you that if your syringe tube slips or falls into tranny that may cuase way more work then anyone wants to do for a simple fluid flush n refill.

I suppose it could be possible to suck out much of the trans fluid that way, but you won't get all of it, and when you refill, you'll just be contaminating the new fluid by adding it to the dirty fluid and filter. The best way is still to drop the pan to change the filter, and that will drain all of the fluid at the same time.

Just to let ya know there is about 8 quarts in that trans. if you are just going going to remove some to lower the level then i think it would work but the biggest question is y are you doing this

i agree with "Doc".

not only will you not get it all, but you will not be able to perform a vital inspection for metallic or particulate matter as most will settle in the bottom of the pan.

then there's the filter.

if there is a reason to change the fluid, then there is a reason to do the inspection.