Most likely some lube has gotten on the blades, sticking them together. Best way to get to the problem is through the front.
There are two narrow slots in the name ring (between Minolta and Rokkor, and between 1.8 and f) where you fit a spanner to remove the ring, turning counter-clockwise. If you don't have a spanner, you can make one from a double ended utility knife blade. Make sure to grind off the edge before doing anything else. Then break off the ends until it fits across the name ring.
After you get off the name ring, you'll be able to see how the rest of the lens/shutter assembly is put together. Could be screws, could be more spanner rings. You may have to order some tools for further dis-assembly, unless you already have a set. Here is a good source
http://www.micro-tools.com/store/home.aspx
I've never worked on a Minoltina, but it should be a fairly straight forward camera to work on, if you've done others like it. The main thing is getting the shutter out so you can clean the blades. Although some will say you can just put some drops of lighter fluid in the shutter in situ, I prefer to get it off the body, and at least do a good flush. Sometimes, it's bad enough that you have to remove and clean each individual blade. Hopefully not in your case. Others have had success working strips of paper in between the blades, and then a drop or two of lighter fluid. The paper wicks the oil away, but has to be repeated more than once. Good chance of damaging a blade or two if you slip-up.
When removing the shutter body from the camera, two things you'll have to watch out for are the wire from the flash sync, and how the cocking mechanism is arranged. There should be a retaining ring on the inside of the camera that holds the lens/shutter assembly to it. Once off the camera, remove all the lens elements from the shutter body, then you can flush it with the lighter fluid, making sure to blow it out to speed up the drying, and operate the shutter and aperture multiple times to make sure the fluid is getting all the oil, and is evaporated.
On some cameras, the lens/shutter assembly is on a plate held on by four screws hidden under the covering. This may be an easier way to remove the lens/shutter assembly.
You could do a search for this particular camera to see if anyone has photos of a tear down to see what all is entailed.
Good luck.
PF
