Replacing bathroom sinks

[Ouch!]

Hello, first time posting here. The 35 year old sinks in me bathroom are rusted and need to be replaced.
When the sinks where installed they were set in the counter then tiled in. It appear the only way to remove them is to take out the tile. The sinks are made from what looks to be very thin steel. I wondering if they could be cut out with a saws all. Then replace them with drop-in and self rimming sinks. The cut out is about 18" x 15" oval, I think a 20" x 17" sink would fit the opening OK. Would this be a good idea? Is there another option.

Thanks for any advice you may offer.

 

[Gary Swart]

The tile covers the sink's rim, so you must remove some tile then and a putty knife under the sink rim to break the sealant that (probably) is under the rim. Then lift the sink out. Measure the opening. Your new sink can not be smaller than the existing opening, but it could be large if you trim the opening. Replace the tile so that the new drop-in sink will cover. This would be good time to consider whether you want to change the counter top or not.