If it is that annoying, just pop the key off. Take an old fashioned flat head screwdriver and gently pry at the edge of the key. To put the key back on, just press it down onto the stud from which it came.
If you are typing in Word, you can also highlight all the text and "Change case" of the text to Sentence Case. On the "Home" tab, in the Font section, left click the icon that has a capital 'A' with lower case 'a' beside it. You can then select the case you want.
If you've done hordes of typing in another program, it might be quickest to copy/paste it into Word, then change case, then copy/paste it back into the original document.