Guitar

You can try it but I wouldn't... the strings don't attach the same way and you might not want to count on the necks and joints of a classical to hold up under the added tension long term. A classical guitar doesn't typically have an x braced top and back either. They tend to use old school glues on guitars intended for nylons so you could easily destroy your guitar with heavy steel strings. Picture your top getting cracks and the slowly bridge pulling up and you won't be too far off.

You can get a decent korean acoustic guitar for a couple hundred semolians. Less used.

You can get a decent korean acoustic guitar for a couple hundred semolians. Less used.

I second this opinion of Jim's. I'd also say that you'll get so much more out of having a proper steel string than you'll get out of converting over a classical.