I have a Mr. Coffee Single Serve Brewer BVMC-KG5. I removed the drip tray and drip tray plate to wash but now I can't seem to put it back on. Does anyone know how to put it back?

Call Keurig @ 1 (866) 901-2739. The Companies to most of your products, are generally very good in helping you with issues. Best regards!

You could try what this guy did with his http://www.youtube.com/watch?v=BWP_vn4uHew

This is a great trouble shooting site, I have been using to answer other peoples' questions;
http://www.mrcoffee.com/service-%26-support/product-support/product-faqs/single-cup-%28brewers%29/bvmc-kg6/BVMC-KG6-faqs.html

Check to make sure nothing is lodged in the way. Let me know!

It depends where the water just "drips out". It could be a leaking hose, or it could be the parts weren't put back together properly after you cleaned it. More information would be helpful.
Download Mr Coffee BVMC KG5 Manual

Use a clean paper clip to clean out any blockage. Let me know how it goes!

Brewer Head open or water is needed.
The KG5 has trouble reading RO or distilled water, for whatever reason. Here is a site that may be helpful; http://www.mrcoffee.com/service-%26-support/product-support/product-faqs/single-cup-%28brewers%29/bvmc-kg6/BVMC-KG6-faqs.html

First clean and please try again
Fill the reservoir with water.
Place your mug underneath the machine.
Add the K-Cup.
Choose your serving size.
Press the brew button to begin brewing.
Enjoy your delicious cup of coffee! .

try going to Mr. Coffee and ask. All you need to do is clean the jet with a paper clip! yeeesh!!! <http://www.mrcoffee.com/service-%26-support/product-support/product-faqs/single-cup-%28brewers%29/bvmc-kg5/BVMC-KG5-faqs.html>

It may be the heating element or thermostat is bad. Try cleaning the heating element and removing any debris.
Download Mr Coffee BVMC KG5 Manual