如何更改DataGridView中所有突出显示的行 - VB.NEt

Begginer's question. I'm trying to write small piece of code in Visual Studio (VB.net) that will change value of a particular field of the database for all highlightetd rows. So, I'm running my form, which displays some data from the datatabse. I then highlight some rows (holding Ctrl and clicking). Next I click a button that will trigger a value change for all the highlighted rows (only). Say, I want to change the "Name" column's value for all of them. Begginer's question. I'm trying to write small