Is it difficult to alter sheer viscose fabrics?

[misspym]

Hi, I have two tops I bought online that I love but are a little oversized and not very flattering on me.

I am thinking of taking them to a dressmaker to be altered but just wondering if it is a difficult job to alter very sheer viscose fabric. It is the kind of fabric you would wear a camisole under as it is quite see through.

Thanks

Should have said both tops need taking in and one also needs to be shortened.