How to claim a personal exemption

You enter yourself, spouse and any dependents under Personal Info.  If you are asking about yourself go to Personal Info and click Edit by your name.  Then scroll down to #3 and it asks......
Someone else can claim me as a Dependent,  Answer  yes or no.  You have to say NO to get your own personal exemption.

Each personal exemption is $4,050 subtracted from your income before the taxes are calculated.  Exemptions are on
1040 line 42
1040A line 26

Or for a 1040EZ the 4,050 is included on line 5 with the 6,300 standard deduction.  
So for Single line 5 would be 4,050+6,300 = 10,350
For Married line 5 would be 8,100+12,600 = 20,700