If you need to raise the soil level go for it. Carefully dig the Hostas with a good bit of earth still attached pop them into bags or pots with a label for each if you have them. Water them and put into shade. Prep the area and replant, water them well.

If you do it on a cool day or in the evening even better. I like to move plants when it is overcast and drizzling rain. They won't even know they were moved.

Now is the time to do it. Hostas are tough and hard to kill. Peren.all gave you good advice

Thanks so much. I just don't want to do anything that will stop them from growing well this year. This gives me a little more confidence.

Soon the slug problem will start. A garden centre where I bought some hostas from said to spray the entire hosta with amonia/water mixture and that will keep the slugs away. Have any of you tried that? I tried the slug bait, diatomaceous earth and the saucer of beer last year and that didn't help much. Some of my hostas were eaten alive. So I need something different this year.

I have not but plenty of people do on The Hosta Forum

They use it at usually a ratio of 1 : 10, that is one part amonia. They say it is most effective when sprayed directly on the slugs.

Do you do a fall cleanup of leaves and debris? I find this is the best way to drastically reduce your slug population. The debris is a perfect breeding ground for slugs. Slug eggs look like small clear caviar so destroy those too if you spot them.

If you wanted info from folks that use the amonia spray you could post to the link provided.