94 camry v6 is leaking coolant from the cap. Cap has a plastic cover that says do not remove or fill from this spot. Can this plastic cover be removed to replace the radiator pressure cap? And how is this plastic cover easily removed without breaking it? Please answer ASAP

The cap only says that so that you don't open it while the engine is still HOT. Doing so can spray hot coolant all over you because the system is pressurized. Wait until the engine is cool and then replace the cap with a new one.

Despite the warnings, you can top off the radiator from the filler neck as long as you do it when the engine is cool. In fact, it is the only way to get all of the air out of the system if it is very low (where you cannot see the liquid level, just the metal innards). In some cases you can hear the gurgling sound as the air bubbles circulate through the cabin heater core.

To purge the air from your cooling system:
Park the car slightly nose-uphill and let it cool. Feel the radiator cap first...don't remove it unless it is just barely warm. Then remove the radiator cap and top it off until the liquid level is just starting to fill the neck. Then slowly squeeze the upper radiator hose to expel any air, stopping when the level gets to the very top of the filler neck. Squeezing too fast will just cause the coolant to slosh back out of the fill neck. Refill right up to where the level is just below the wider part of the neck top. Cap it off and refill the overflow reservoir up to about 1/3 full. Drive the car and get it warm. Then stop and check it again once it has cooled. The coolant level in the radiator should be completely full, up to the neck. If not, repeat.

Don't forget to use the correct coolant as listed in your owner's manual. Toyota uses a red-colored coolant which you can probably buy at any auto parts store or dealer...look for a 50/50 premixed jug since this is the easiest to handle. If not, you'll need to add equal amounts of the coolant and distilled water...I usually keep an old coolant jug handy for mixing. Some even have markings on the side and a way to see the level in the jug. Makes mixing easy.

Hope this helps!