Macro to Perform Find and Replace Function Please HELP!

I have searched for this and came across many posts but none seem to work. I have two sheets. One is named sheet1 where all my data is and sheet2 where all my values are. I want to do a find a replace on column N (sheet1) using the data in sheet2. Column A on Sheet2 has all the values that are found in column N and column B on Sheet2 has what the data should change to.

So for example:

Sheet1 says the following on column N:

cat
dog
lion
bear

Sheet2 says:

Column A
A1: Cat
A2: Dog
A3: Bear


Column B
B1: 2
B2: 8
B3:15

I want the values on column N to be replaced with 2, 8, 15 and so forth. I use excel 2010. Thanks in advanced for your help!!!