step 1
Start from home screen and go to Settings

step 2
Go to General

step 3
Choose Networks

step 4
Go to VPN

step 5
Tap on Add PPTP Configuration… option.

step 6
Choose PPTP tab
Fill form with your details:
Desription – Any name, not critical. Can be SafeVPN
Server – Your server IP here
Account – Your Username here
RSA SecureID – keep it Off
Password – Your Password here
Encryption Level – keep it Auto
Send All Traffic – keep it On
Proxy – keep it Off
Save using button in right top corner the Configuration