Yes, they can be changed. You can purchase a weight kit through the Scotty Cameron website. Below is the link to the heavy kit.

www.scottycameron.com/.../product.aspx

yes, you just need the weight tool which you can obtain from scottycameron.com along with whatever weight you desire.

You can get them changed out, I sent mine to the Scotty Cameron custom shop and one of my changes was to swap out the weights for 25g weights. They sent me back my original weights with a tool in case I wanted to put the original weights back on.

Depending on what model you have Scotty Cameron’s website may have a weight kit for you. Otherwise you could send it to Scotty’s custom shop as those weights should be able to be changed.
Although the Scotty Cameron putters are weighted based on length of putter.

Yes, authentic weights can be purchased directly from the Scotty Cameron website. You can also send the putter in to the Scotty Custom Shop for them to do the work for you.

You obviously have a 34" putter. They are very easy to change if you have the proper tools. Getting the kit from Scotty that Andrew suggested is a great option in the event you like to tinker around. I changed by Newport 2 Notchback 35" 10gr to a 15gr, just felt it was too light and love the difference it makes. I bought just the weights I needed thru authorized Titleist dealer. Happy putting.