(If I can first make a remark directed at someone else's answer to this question - LOL dabeaner. My head didn't go anywhere near that direction when I saw this question.)
In all seriousness, I think before anyone thinks about disposing of a love one's clothes he should feel emotionally ready to do that. Some people will feel ready sooner than others, but it always happens sooner or later.
I think the first step is just putting the clothes away in the house somewhere. The next thing is being ready to go through them and decide which items are in good enough shape to be worn by someone else. Giving them to charity can give you the feeling that "at least someone who needs clothes will get the benefit of them". Some charities make minor repairs on clothes (and provide people, like mentally disabled people, with work/jobs); so if minor repairs are needed and you're giving to a charity make sure it's one that isn't looking for "good and usable" clothes and, instead, is one that makes repairs.
If the clothing items are really worn and couldn't be used by someone else (even with minor repairs) I think you have to just bag them up and wait until you're ready to throw them out. If throwing them out is too difficult for you, bag them up, let the bag sit for a little while, and ask someone else to throw it away for you.
I don't think people need to feel it's important to get rid of absolutely every piece of clothing someone had. Keeping a special few pieces in a box somewhere (maybe, for example, to show great-grandchildren the kind of clothes Great-Grandma wore "back in the day" - or maybe just because you want to save "Grandpa's special hat" or military uniform) is something a lot of people do.