Start with Hiroyuki Nakajima. Here's a very long description of him. The short version: Ever since the New York Mets signed Kaz Matsui he's been the star shortstop of the Seitama Seibu Lions. In the last two years, he's hit (right-handed) .303/.367/.441 with some doubles and some home runs. The Oakland Athletics signed him to a two-year, $6.5 million contract, because nothing good can happen to me, anymore. Here's how you turn him into Ty Wigginton.
1. Take $1.5 million away. This is the good part. You get $750,000 a year to spend on whatever you want, so long as it's a baseball player.
2. Adjust for league. Major League Baseball is better than Nippon Professional Baseball, so make an adjustment for that. But you'll also have to make an adjustment for league context. The American League, where Ty Wigginton played last year, much to your surprise, hit .255/.320/.411 last year, because it is the Dead Ball Era and Greg Vaughn isn't allowed to hit 50 home runs anymore. The Pacific League, where Hiroyuki Nakajima played for the last two years, hit .251/.311/.347 in 2012 and .251/.308/.348 the year before that, because they literally introduced a deadened ball.
Figure out a way to make adjustments such that Nakajima's .303/.367/.441 line over the last two seasons (since the introduction of the dead ball--the year before he hit .314/.385/.511) turns into Ty Wigginton's .239/.314/.398 line over the last two seasons. It will help to ignore their ages. Before his OPS went up 50 points between 2011 and 2012 Dan Szymborski projected his OPS+ at 89, which is better than Wigginton managed in 2011 or 2012.
Hiroyuki Nakajima projects at 276/322/389, OPS+ 89 in Yankee Stadium— Dan Szymborski (@DSzymborski) December 12, 2011
3. Adjust for defense. Major league scouts are not extremely confident about Hiroyuki Nakajima's ability to play shortstop full-time, which is a thing he has in common with Ty Wigginton. You will want to find some way to turn Nakajima's bad shortstop defense into Ty Wigginton's bad third base defense.
Wigginton, for his career, is a minus-18 third baseman per 1,200 innings and, somehow, a minus-seven first baseman per 1,200 innings. The positional adjustment between a shortstop and a third baseman is five runs; for a first baseman it's about 20. A good example of a -23 third baseman is usually moved to first base before he reaches the major leagues, unfortunately.
4. Go into your bathroom and turn the lights off. Scream "Tsuyoshi Nishioka" over and over until he appears inside the mirror and tells you how you'll die.