Confused bestway to refresh dinning room chairs

[ih]

My oh wants to refresh dinning table chairs but she has no clue what has to be done and is looking for
Step by step guide to achieve this she is ok with brush but is not sure if this is spray or paint job also thoroughly
Confused between varnish/stain/dye/paint thanking in advance
Attached photos
Regards

 

[opps]

They look like they might have french polish on them. French polish is shellac based. To test it, wet a cloth with meths and rub a section. If it becomes gooey, it is shellac. You can then "re-polish" it to freshen it up. French polish is quite easy to apply to small sections. A whole table is harder work

If it is varnish you will need to sand it thoroughly prior to revarnishing or painting.

Spraying would be far easier than painting but you might need to hire equipment and will need to create a workspace to deal with any overspray.