New here and to 3d printing, bought it earlier this year and have been using it to print off test pieces of my cad drawings before having them machined.

I was recently asked to print a couple of figure models which I didnt think I would ever use the printer for but accepted out of curiosity and thought it would be handy to learn.

One stl file i purchased was fine for the job but the second I would like to modify.

I got the baby yoda with heart stl and have scaled it down to 60% but I would like to make it not hollow, at this smaller size it is a bit fragile and id like to make it solid to increase the strength but all i seem to be able to do is make the walls solid. I filled one with resin to get around this but it didnt fill the head and when i dropped the model the head split.

Is there anyway I can make the centre of this solid?