How to change my 4digit pin code at the front screen of my iPad mini

Use the Settings app.

Settings > Passcode > Enter your present passcode > Change Passcode

You can only do that once the iPad is unlocked so of you forgot the passcode, you have to restore your iPad. Be prepared to lose all of your data as well. If you have a backup, you will be able to restore from the backup when you are done restoring the device.

Read this for more details.

iOS: Forgotten passcode or device disabled after entering wrong ...

I received a notice that there was an update due. So, I thought "Cool!" and installed it. However, one thing that it asked for was a for four-digit pass code. My iPad did not include one of those originally because my computer son (who is a good engineer who works with computers for his living, and he is really, really good. I used to be very good, too, until I had a stroke.) Anyway, this has gone on too long!

Ok, forget all that. Sorry.

The problem is that I forgot my 4digit pin code. Can you please help me?

Thank you!

Rebecca ****
<Personal Information Edited by Host>

Follow these instructions : If you forgot the passcode for your iPhone, iPad, or iPod touch, or your device is disabled - Apple Support

(As these are user-to-user public forums I've asked the hosts to remove your email address from your post - it's not a good idea to post personal info on any public forum.)