shopify_api_redirect_upload.rb

require 'httparty'

redirects = [ # FIELD1 is the current URL; FIELD2 is the URL you want the user to be redirected to.
 {
   "FIELD1": "http:\/\/www.myshop.com\/products\/urban-camo-tracksuit",
   "FIELD2": "http:\/\/www.myshop.com\/collections\/tracksuit\/products\/urban-camo-tracksuit-bottoms"
 },
 {
   "FIELD1": "http:\/\/www.myshop.com\/products\/urban-camo-vest",
   "FIELD2": "http:\/\/www.myshop.com\/collections\/mens-vests\/products\/kutula-urban-camo-vest"
 }
]

redirects.each do |redirect|

  redirect_item = { # generate an object in the correct format for Shopify
    "redirect": {
      :path => redirect[:FIELD1],
      :target => redirect[:FIELD2]
    }
  }

  @result = HTTParty.post('https://josie-anna.myshopify.com/admin/redirects.json',
    :body => redirect_item.to_json,
    :headers => { 'X-Shopify-Access-Token' => 'YOUR_PRIVATE_APP_PASSWORD_GOES_HERE', 'Content-Type' => 'application/json' }
  )

  puts @result # log the result to the console
  sleep 5 # wait 5 seconds before submitting the next redirect item

end

Bulk upload redirect rules via the Shopify API. All you need to do is create a private app, and then create a list of redirects you want to send to Shopify. This is a Ruby script, so you will need Ruby installed to run the script.