Burnt out LED

So I am not very familiar with LEDs...

Here is some background on my setup. I purchased an LED setup from someone who already had built it, but had to sell it for some reason or another. Everything worked fine. We recently decided to mount the setup in our canopy. I think that we must have knocked one of the lights, because some of them are now significantly dimmer (the whole left side).

I believe the way they are wired are in series, with a total of four circuits. It is easy to notice the difference because the left side of the tank has much less white.

To test where the problem was occurring, I simply took some picture wire and provided an alternative path for the current to travel (as it will obviously take the path of least resistance). I placed the wire on either side of the burnt out/broken led. This fixed it (momentarily...). So the problem is at the site of the burnt out/broken LED.

I do not have a soldering gun. I would like to replace this single bulb/unit/whatever it is called. I would like to replace it with one of the following products:
Solderless CREE XP-G 5W Cool White LED (old version) - Rapid LED
Solderless CREE XP-G Cool White LED - Rapid LED

Here are my questions.
1) My current bulbs are 3W Crees. Is it okay to replace a single 3W Cree with a 5W cree?
2) Are there any other factors that I should take into consideration here? Or any precautions that I should take to prevent damaging the other bulbs or entire system? Like I said, I am totally new to LEDS. The the only thing I am familiar with is what I learned about electricity/circuits in college physics ;D

 

The 5 watt crees are 3 watt at lower voltages, if you can splice a wire, you can use their kit. Just make sure you unplug the drivers first.

 

One more question. The first link that I posted up there seems like you need to purchase LED terminal as well, which I don't want to do.

The second link seems like I need to wire each LED in parallel? Can I just plug a total of two wires into this contraption (to make it in series)? For reference:
Solderless CREE XP-G Cool White LED - Rapid LED
Here is a diagram they provide
http://www.menarilighting.com/rapidled/documentation/RapidLED_Solderless_Wiring_Diagram.pdf
Also, what is the solderless led plug they mention? Do i need this?
Solderless LED Plug - Rapid LED

 

Honestly the best advice would be to sit down with a LARGE cup of coffee and a whole day (or three) ahead of you. Hate to say it but RC has their infamous LED thread and it's about 173684 pages but you can literally find everything in there. The thing with LEDs is that with one little mistake you can blow a whole circuit!!!
So you should first learn about your drivers, then learn how to calculate the voltage across each series (a voltmeter comes in handy), also read up on how to adjust the amperage, etc. Another useful thing would be to check into if the drivers are dimmable and whether or not they are PWM or not. You probably have a ton of questions but I should have a ton of answers haha!
When questions arise you can call or message me. I should be able to help with most things.

 

The old solderless kits required you to plug the LEDs to a central LED terminal, but now the new kits allow you to plug from LED to LED directly (much cleaner look). In order to complete the circuit (remember open circuits are bad in general, and will blow LEDs quite easily) you need a solderless LED plug at the very end of your string to complete the circuit.

If your other LEDs are the regular solder type I don't recommend mixing the solderless items with them unless you can trace the circuit and make sure everything is going in the right order (ie. + to - between LEDs, etc).